21395

Appears in sequences

• Convolution of A000203 with itself.at n=34A000385
• 1 + n-th prime is harmonic.at n=8A074692
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (0, 1, 1), (1, -1, 0), (1, -1, 1), (1, 1, -1)}.at n=8A149492
• Number of ordered octuples of distinct pairwise coprime positive integers with largest element n.at n=20A186979
• Number of 7-element subsets of {1, 2, ..., n} having pairwise coprime elements.at n=23A186983
• Number of 2 X 2 matrices having all terms in {1,...,n} and determinant d satisfying -n < d < n.at n=18A211070
• Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, vertical or antidiagonal neighbor, and containing the value n(n+1)/2-2.at n=19A211924
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1)^2, where a(0) = 3, a(1) = 4, b(0) = 1, b(1) = 2, and (a(n)) and (b(n)) are increasing complementary sequences.at n=14A296256