21843

Appears in sequences

• Number of partitions of n into parts of 3 kinds.at n=14A000716
• a(n) = A027113(n, 2n-1).at n=10A027119
• Number of length 3 walks on an n-dimensional hypercubic lattice starting at the origin and staying in the nonnegative part.at n=27A064043
• a(n) is the index of the first occurrence of n in A080071, or 0 for those n>0 which never occur in A080071.at n=14A080090
• Numbers n such that (n+j) mod (2+j) = 1 for j from 0 to 6 and (n+7) mod 9 <> 1.at n=17A096025
• Numbers n such that sigma(n) and sigma(sigma(n)) are both perfect squares.at n=29A134263
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (-1, 0, 1), (-1, 1, 1), (1, 0, 0)}.at n=10A148550
• First differences of A135351.at n=18A155980
• a(n) = (2*2^n+7*(-1)^n)/3.at n=15A171382
• Numerator of sum(i=1..n, 3*i/4^i ).at n=7A215712
• Irregular triangle read by row: T(n,k), n>=1, k>=1, in which column k lists the numbers of A000716 multiplied by A000330(k), and the first element of column k is in row A000217(k).at n=40A252117
• Number of (n+2)X(5+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=6A254904
• Number of (7+2) X (n+2) 0..1 arrays with every 3 X 3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=4A254913
• Numbers k such that 6*10^k + 91 is prime.at n=29A265938
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 534", based on the 5-celled von Neumann neighborhood.at n=42A272788
• Number of nX7 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=2A302471
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=38A302472
• Number of 3Xn 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A302473
• Number of nX7 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=2A303253
• T(n,k) = Number of n X k 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=38A303254