cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A133603 The matrix-vector product A133566 * A000108.

Original entry on oeis.org

1, 1, 3, 5, 19, 42, 174, 429, 1859, 4862, 21658, 58786, 266798, 742900, 3417340, 9694845, 45052515, 129644790, 607283490, 1767263190, 8331383610, 24466267020, 115948830660, 343059613650, 1632963760974, 4861946401452
Offset: 0

Views

Author

Gary W. Adamson, Sep 18 2007

Keywords

Comments

A133602 is a companion sequence.

Examples

			a(5) = C(5) = 42.
a(6) = 174 = C(6) + C(5) = 132 + 42.
		

Crossrefs

Cf. A133566, A000108, A133602, A024492 (bisection).

Programs

Formula

A133566 * A000108 where A133566 = an infinite lower triangular matrix and A000108 = the Catalan sequence. For odd n, a(n) = C(n). For even n, a(n) = C(n) + C(n-1) = A005807(n-1).
Conjecture: n*(n-2)*(3*n-1)*(n+1)*a(n) -8*n*(2*n-3)*a(n-1) -4*(n-1)*(3*n+2)*(
2*n-3)*(2*n-5)*a(n-2)=0. - R. J. Mathar, Jun 20 2015