A288689 Number of n-digit biquanimous strings using digits {0,1,...,5}.

1, 1, 6, 46, 376, 2841, 19718, 128535, 805848, 4942711, 29970542, 180700389, 1086570460, 6525662885, 39170135870, 235062159691, 1410477973872, 8463133736523, 50779476069198, 304678570340665, 1828075815690100, 10968466276145161, 65810827526263678

Offset

0,3

Comments

A biquanimous string is a string whose digits can be split into two groups with equal sums.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (23, -231, 1351, -5153, 13557, -25301, 33829, -32226, 21368, -9376, 2448, -288).

Formula

G.f.: (144*x^14 -1224*x^13 +4976*x^12 -11002*x^11 +18115*x^10 -25255*x^9 +30319*x^8 -29516*x^7 +21747*x^6 -11691*x^5 +4506*x^4 -1212*x^3 +214*x^2 -22*x +1) / ((6*x-1) *(3*x-1) *(2*x-1)^4 *(x-1)^6).

Crossrefs

Column k=5 of A288638.

Sequence in context: A334609 A253654 A301421 * A271933 A380685 A084772

Adjacent sequences: A288686 A288687 A288688 * A288690 A288691 A288692

Keyword

nonn,easy

Author

Alois P. Heinz, Jun 13 2017

Status

approved