21819

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 98.at n=38A031596
• Number of compositions of n with exactly 1 adjacent equal pair of parts.at n=16A106357
• A partition product of Stirling_1 type [parameter k = -3] with biggest-part statistic (triangle read by rows).at n=29A157383
• A partition product of Stirling_1 type [parameter k = 3] with biggest-part statistic (triangle read by rows).at n=29A157393
• A partition product of Stirling_2 type [parameter k = -3] with biggest-part statistic (triangle read by rows).at n=29A157399
• A partition product of Stirling_2 type [parameter k = 3] with biggest-part statistic (triangle read by rows).at n=29A157403
• Triangular array read by rows: T(n,k) is the number of endofunctions f:{1,2,...,n}-> {1,2,...,n} whose largest component has exactly k nodes; n>=1, 1<=k<=n.at n=29A209324
• Least number having n orderless representations as p^2 + q^2 + r^2, where p, q, and r are primes.at n=15A214512
• Number of (4+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=7A250759
• Number of (n+2)X(5+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7.at n=3A252404
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7.at n=31A252407
• Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7.at n=4A252411
• Triangle read by rows: T(n,k) is the number of subpermutations of an n-set, whose orbits are each of size at most k with at least one orbit of size exactly k, and without fixed points. Equivalently, T(n,k) is the number of partial derangements of an n-set each of whose orbits is of size at most k with at least one orbit of size exactly k, and without fixed points.at n=38A261765
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 105", based on the 5-celled von Neumann neighborhood.at n=31A270162
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 734", based on the 5-celled von Neumann neighborhood.at n=34A273455
• Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=7A300918
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=47A300923
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=52A300923
• Irregular table whose rows list the nontrivial cycles of the ghost iteration A329201, starting with the smallest member.at n=5A329342
• a(n)/2^(n-1) is the expected win if one of two baskets is chosen randomly and the player optimally chooses the coins with values from 1 to n (see Comments for details).at n=9A391791