20276

Appears in sequences

• Numbers k such that k*k! - 1 is prime.at n=25A090704
• Index of first occurrence of n-th prime in A001203, the continued fraction for Pi.at n=42A107892
• 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, 0, 1), (0, -1, 1), (1, 1, -1), (1, 1, 0), (1, 1, 1)}.at n=7A151012
• a(n) = number of ways to write n as a sum of distinct numbers <= n, where the addition is carryless mod 10.at n=22A169973
• Partial sums of A050508.at n=33A178129
• Triangle T(n,k) giving the number of terms of A219666 which have n digits (A084558) in their factorial base expansion and whose most significant digit (A099563) in that base is k.at n=36A230420
• Triangle A230420 transposed.at n=44A230421
• Number of Sidon subsets of {1,...,n} of size 4.at n=29A241688
• Absolute discriminants of complex quadratic fields with 3-class rank 2.at n=22A242862
• Absolute discriminants of complex quadratic fields with 3-class group of elementary abelian type (3,3) of rank 2.at n=13A242863
• Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) and Hilbert 3-class field tower of exact length 2.at n=5A242864
• Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) and 3-principalization type (4224).at n=2A247690
• Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) whose second 3-class group is located on the sporadic part of the coclass graph G(3,2) outside of coclass trees.at n=8A247691
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 589", based on the 5-celled von Neumann neighborhood.at n=14A283173
• Consider all ways of writing the composite Fibonacci number A090206(n+3) as product of two divisors d1*d2 = d3*d4 = ... The sequence a(n) gives the minimum sums of {d1+d2, d3+d4,...}.at n=28A287273
• Partial sums of the ziggurat sequence A347186.at n=44A356351