34380

Appears in sequences

• Numbers k such that the sum of the divisors of 2*k^2 is a square.at n=7A097023
• Triangle T(n, k) = binomial(n, k) * A000085(n-k), 0 <= k <= n.at n=57A111062
• Square array, read by antidiagonals, where row n+1 is generated from row n by first removing terms at positions [(m+3)^2/4 - 2] for m>=0 and then taking partial sums, starting with all 1's in row 0.at n=38A135878
• Triangle, read by rows, equal to the matrix cube of triangle P = A135880.at n=21A135888
• Column 0 of triangle A135888, which equals the matrix cube of triangle A135880; also equals column 1 of triangle A135894.at n=6A135889
• Triangle R, read by rows, where column k of R equals column 0 of P^(2k+1) where P=A135880.at n=29A135894
• Triangle, read by rows equal to the matrix product R^-1*Q, where Q = A135885 and R = A135894; R^-1*Q equals triangle R shifted down one row.at n=37A135900
• a(0) = 0, a(1) = 1, a(n+1) = (2*n^2+2*n+21)*a(n) - n^4*a(n-1).at n=4A142998
• Partial sums of A160414.at n=32A161325
• Number of 2-cycles in all involutions of {1,2,...,n}.at n=9A162970
• Triangle read by rows: Ranks of ideals in Partial Brauer Monoid PB_n.at n=57A276774
• Number of compositions of n into parts with distinct multiplicities and with exactly nine parts.at n=25A321779
• a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero icosahedral numbers in exactly n ways, or -1 if no such integer exists.at n=29A360215