19815

Appears in sequences

• a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n+1-k), where k = [ (n+1)/2 ], s = A001950 (upper Wythoff sequence).at n=31A024689
• s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A001950 (upper Wythoff sequence).at n=30A025122
• Half the number of length n integer sequences with sum zero and sum of squares 242.at n=4A157543
• Transform of A056594 by the T_{1,1} transformation (see link).at n=11A159334
• a(n) = 2^n + binomial(n, floor(n/2)) - 1.at n=14A261681
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 217", based on the 5-celled von Neumann neighborhood.at n=30A270911
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A381574.at n=49A381573
• a(n) is the index of A384793(n) in A038618.at n=44A384794