23913

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (odd natural numbers), t = A000201 (lower Wythoff sequence).at n=43A025113
• Decimal part of 1/a(n) starts with Fibonacci(n) (leading zeros excluded).at n=18A099405
• Number of nonisomorphic graded posets with 0 and non-uniform Hasse graph of rank n, with exactly 2 elements of each rank level above 0.at n=8A206948
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 369", based on the 5-celled von Neumann neighborhood.at n=32A268503
• Consider any concatenation of the type n = concat(a,b). Sequence lists numbers whose reverses are the sum of the products of some of such couples a and b.at n=10A281555