21158

Appears in sequences

• Greedy frac multiples of Catalan's constant, G: a(1)=1, Sum_{n>0} frac(a(n)*x) = 1 at x=G=A006752, where "frac(y)" denotes the fractional part of y.at n=4A080158
• Number of subsets S of {1,2,...,n} which contain a number that is greater than the sum of the other numbers in S.at n=33A095944
• a(n) = (n - 2/3)*2^n - n/2 + 3/4 - (-1)^n/12.at n=10A127983
• Numbers n such that sigma(n) and sigma(sigma(n)) are both perfect squares.at n=27A134263
• Number of (n+1) X 2 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock differing from the number in all its horizontal and vertical neighbors.at n=8A205065
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock differing from the number in all its horizontal and vertical neighbors.at n=36A205072
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock differing from the number in all its horizontal and vertical neighbors.at n=44A205072
• Irregular triangle read by rows: row n gives numbers of maximal chains of lengths n-1, n, n+1, ... in the Tamari lattice T_n.at n=34A282698
• Number of permutations of [n] avoiding {4231, 1243, 1234}.at n=11A294762