A288688 Number of n-digit biquanimous strings using digits {0,1,...,4}.

1, 1, 5, 31, 201, 1206, 6751, 36051, 187025, 954136, 4822527, 24251877, 121631329, 609151986, 3048441935, 15249510871, 76267672545, 381394509228, 1907131201327, 9536109476745, 47681856564305, 238413094649734, 1192076649237855, 5960416195898811

Offset: 0

Author

Alois P. Heinz, Jun 13 2017

Keywords

• nonn
• easy

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 (18, -137, 582, -1527, 2574, -2795, 1890, -724, 120).

Crossrefs

Column k=4 of A288638.

Formula

G.f.: -(60*x^10 -422*x^9 +1044*x^8 -1855*x^7 +2394*x^6 -2122*x^5 +1273*x^4 -504*x^3 +124*x^2 -17*x +1) / ((5*x-1) *(3*x-1) *(2*x-1)^3 *(x-1)^4).