A197192 a(n) = binomial(n+9, 9)*7^n.

1, 70, 2695, 75460, 1716715, 33647614, 588833245, 9421331920, 140142312310, 1961992372340, 26094498552122, 332111799754280, 4068369546989930, 48194531556649940, 554237112901474310, 6207455664496512272, 67894046330430602975, 726865672478727631850, 7632089561026640134425

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..400

Formula

a(n) = C(n + 9, 9)*7^n.

From Amiram Eldar, Sep 29 2025: (Start)

Sum_{n>=0} 1/a(n) = 105815808*log(7/6) - 652463109/40.

Sum_{n>=0} (-1)^n/a(n) = 1056964608*log(8/7) - 5645518203/40. (End)

Mathematica

Table[Binomial[n+9, 9]7^n, {n, 0, 20}] (* Harvey P. Dale, Jul 10 2025 *)

Prog

(Magma) [Binomial(n+9, 9)*7^n: n in [0..20]];

Crossrefs

Cf. A139641, A140107, A140404, A170932.

Sequence in context: A017786 A035730 A017733 * A213468 A004377 A069296

Adjacent sequences: A197189 A197190 A197191 * A197193 A197194 A197195

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 13 2011

Status

approved