55684

Appears in sequences

• Number of n X 3 binary arrays indicating whether each 2 X 2 subblock of a larger binary array has lexicographically increasing rows and columns, for some larger (n+1) X 4 binary array with rows and columns of the latter in lexicographically nondecreasing order.at n=9A227086
• a(n) = 2*a(n-2) + a(n-3) + a(n-4) for n>=4, a(n) = binomial(n,3) for n<4.at n=25A240607
• Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 2 and no column sum 2.at n=22A255221
• Expansion of 1/(1 - Sum_{k>=0} x^(2*k*(k+1)+1)).at n=40A282504
• Number of partitions of the n-th triangular number into exactly n positive triangular numbers.at n=23A338585