31956

Appears in sequences

• Number of step cyclic shifted sequences using exactly four different symbols.at n=10A056417
• Number of primitive (period n) step cyclic shifted sequences using exactly four different symbols.at n=10A056426
• Even pseudoprimes to base 37.at n=22A130441
• G.f. satisfies: A(x) = Sum_{n>=0} x^n*A(x)^A001951(n), where A001951(n) = [n*sqrt(2)].at n=10A190270
• a(n) = 9*n^3/2 - 21*n^2/2 + 8*n - 4.at n=18A232495
• Number A(n,k) of endofunctions on [n] such that no element has a preimage of cardinality k; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=51A245405
• Number of endofunctions on [n] such that no element has a preimage of cardinality three.at n=6A245407
• Partial sums of A255745.at n=25A255766
• Number of n X 4 binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.at n=4A268882
• T(n,k)=Number of nXk binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.at n=32A268886
• Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.at n=3A268890
• Number of permutations of [n] avoiding {4231, 3142, 1234}.at n=12A294726
• a(n) = smallest k such that li(k) - pi(k) >= n, where li(k) is the logarithmic integral and pi(x) is the number of primes <= x.at n=38A359145