A036224 Expansion of (-1+1/(1-6*x)^6)/(36*x); related to A036084.

1, 21, 336, 4536, 54432, 598752, 6158592, 60046272, 560431872, 5043886848, 44019376128, 374164697088, 3108445175808, 25311625003008, 202493000024064, 1594632375189504, 12381851383824384, 94927527275986944

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (36, -540, 4320, -19440, 46656, -46656).

Formula

a(n) = 6^(n-1)*binomial(n+6, 5);

g.f. (-1+(1-6*x)^(-6))/(x*6^2).

Prog

(Sage) [lucas_number2(n, 6, 0)*binomial(n, 5)/6^7for n in range(6, 24)] # Zerinvary Lajos, Mar 13 2009

Crossrefs

Cf. A036084, A036083.

Sequence in context: A095905 A051525 A107396 * A113895 A062260 A278804

Adjacent sequences: A036221 A036222 A036223 * A036225 A036226 A036227

Keyword

easy,nonn

Author

Wolfdieter Lang

Status

approved