19530

Appears in sequences

• Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,3,0.at n=5A037627
• Number of 3 x n binary matrices without unit columns up to row and column permutations.at n=37A057524
• Numbers k such that (1/k) * Sum_{d|k} d*sigma(d) is an integer.at n=11A069520
• Smallest magic constant for any n X n magic square made from consecutive primes, or 0 if no such magic square exists.at n=17A073520
• Product of numbers obtained by adding one to the odd divisors of n and subtracting 1 from the even divisors.at n=31A086535
• a(0) = 0; a(n) = 5*a(n-1) + 5.at n=6A104891
• Triangle T, read by rows, equal to the matrix 5th power of triangle A113106, which satisfies the recurrence: A113106(n,k) = [A113106^5](n-1,k-1) + [A113106^5](n-1,k).at n=26A113114
• (n+n^2+n^3)*(binomial(2*n,n))/2.at n=5A119577
• a(1)=1, a(n) = a(n-1) + (p-1)*p^(n/2-1) if n is even, otherwise a(n) = a(n-1) + p^((n-1)/2), where p=5.at n=11A133629
• Number of 4-way intersections in the interior of a regular 6n-gon.at n=30A137938
• 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, 1, -1), (0, 1, 1), (1, -1, 0)}.at n=11A148173
• 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, 1), (-1, 1, -1), (0, 1, 1), (1, -1, 0)}.at n=11A148174
• Symmetrical Hahn weights on q-form factorials:m=2;q=3; q-form:t(n,m)=If[m == 0, n!, Product[Sum[(m + 1)^i, {i, 0, k - 1}], {k, 1, n}]]; Hahn weight:b(n,k,m)=If[n == 0, 1, (n!*t[m + 1, k]*t[m + 1, n - k])/(k!*(n - k)!*t[1, n])].at n=16A157321
• Symmetrical Hahn weights on q-form factorials:m=2;q=3; q-form:t(n,m)=If[m == 0, n!, Product[Sum[(m + 1)^i, {i, 0, k - 1}], {k, 1, n}]]; Hahn weight:b(n,k,m)=If[n == 0, 1, (n!*t[m + 1, k]*t[m + 1, n - k])/(k!*(n - k)!*t[1, n])].at n=19A157321
• a(n) = 16*n^2 - 2*n.at n=34A158058
• Smallest number which is an unordered sum of two odd abundant numbers in exactly n ways.at n=15A187743
• Triangle by rows T(n,k), showing the number of meanders with length (n+1)*6 and containing (k+1)*6 Ls and (n-k)*6 Rs, where Ls and Rs denote arcs of equal length and a central angle of 60 degrees which are positively or negatively oriented.at n=19A197655
• Number of -7..7 arrays x(0..n+2) of n+3 elements with zero sum and no two or three adjacent elements summing to zero.at n=1A200429
• T(n,k)=Number of -k..k arrays x(0..n+2) of n+3 elements with zero sum and no two or three adjacent elements summing to zero.at n=29A200430
• Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two or three adjacent elements summing to zero.at n=6A200432