26104

Appears in sequences

• a(n) is the concatenation of n and 4n.at n=25A019552
• Number of free orthoplex n-ominoes with cell centers determining n-2 space.at n=9A036367
• Expansion of (1+x^4*C^4)*C^4, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=8A071757
• Natural number transform of Aitken's triangle.at n=34A127740
• Triangle T(n,k) = number of forests of labeled rooted trees of height at most 1, with n labels, k of which are used for root nodes and any root may contain >= 1 labels, n >= 0, 0<=k<=n.at n=43A143396
• 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, 0, 1), (0, -1, 1), (0, 1, 0), (1, 1, 0)}.at n=8A150346
• Number of partitions p of n such that (number of numbers in p of form 3k+1) = (number of numbers in p of form 3k+2).at n=45A241738
• Number of forests of labeled rooted trees of height at most 1, with n labels, seven of which are used for root nodes and any root may contain >= 1 labels.at n=1A273657
• Numbers k such that 435*2^k+1 is prime.at n=47A323146
• a(n) = Sum_{k=0..n} 2^((n + k - 1)*(n - k)/2) * n! / (n - k)!. Row sums of A365638.at n=5A379614