55760

Appears in sequences

• a(n) = n*(n+1)*(5*n + 4)/6.at n=40A162147
• a(n) = Sum_{k=0..n-1} [x^k] A(x)^(n-1) for n>=1 with a(0)=1, where g.f. A(x) = Sum_{n>=0} a(n)*x^n.at n=7A233436
• Number of (n+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the central row and column plus the two sums of the diagonal and antidiagonal nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=2A258999
• Number of (n+2)X(3+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the central row and column plus the two sums of the diagonal and antidiagonal nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=2A259001
• T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the central row and column plus the two sums of the diagonal and antidiagonal nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=12A259006
• Number of (3+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the two medians of the central row and column plus the two sums of the diagonal and antidiagonal nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=2A259008
• a(1) = 1; a(n) = (2^n - 1)*((3^n - 1)/(2^n - 1) mod 1), n >= 2. Unreduced numerators of fractional parts of (3^n - 1)/(2^n - 1).at n=15A297446
• 3-Springer numbers.at n=7A347930