26172

Appears in sequences

• Main diagonal of square table A086620 of coefficients, T(n,k), of x^n*y^k in f(x,y) that satisfies f(x,y) = 1/(1-x-y) + xy*f(x,y)^2.at n=6A086621
• Number of permutations of length n which avoid the patterns 1234, 3421, 4312.at n=35A116756
• Number of 1's in row n of A143589 (a Kolakoski fan).at n=28A143591
• Number of 2's in row n of A143589 (a Kolakoski fan).at n=28A143592
• Triangle T(n,k) by rows: number of ways k dominoes can be placed on an n X n chessboard, k>=0.at n=35A242861
• Number of 3-matchings of the n X n grid graph.at n=6A243206
• a(n) = number of triangles that can be formed from the points of a 3 X n grid.at n=18A262402
• Numbers m such that sigma(m)*tau(m) is a square but sigma(m)/tau(m) is not an integer.at n=9A327831
• a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/(2*k-1))^3.at n=29A350163
• a(n) is the first position where the digits of n occur simultaneously in the decimal expansions of Pi and e.at n=24A381980