20688
domain: N
Appears in sequences
- Number of solid partitions of n supported on graph of cube.at n=27A003404
- Number of trees with n nodes and 10 leaves.at n=7A055297
- Number of primitive (period n) step cyclic shifted sequences using exactly four different symbols.at n=9A056426
- Numbers k such that sigma(k) mod pi(k) = 1.at n=17A073723
- a(n) = C(2,n) DELTA C(0,n).at n=37A147721
- a(n) = 36*n^2 - 2*n.at n=23A158062
- Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 3.at n=39A209986
- Total area of the shadows of the three views of a three-dimensional version of the shell model of partitions with n shells.at n=23A210970
- Number of partitions p of n such that 2*(number of even numbers in p) >= (number of odd numbers in p).at n=38A241654
- Numbers missing from A001033 despite satisfying the necessary congruence conditions (see comments).at n=31A274470
- Number of length-n ternary words that are bi-maximally squarefree.at n=52A323487
- Number of binary toroidal necklaces of size n.at n=16A323859
- Number of integer partitions of n whose parts minus 1 are relatively prime.at n=37A328170
- Number of unlabeled trees covering 2n nodes, n+1 of which are leaves.at n=8A358107