A067420 Fifth column of triangle A067417.

1, 7, 105, 1575, 23625, 354375, 5315625, 79734375, 1196015625, 17940234375, 269103515625, 4036552734375, 60548291015625, 908224365234375, 13623365478515625, 204350482177734375, 3065257232666015625

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..800

Index entries for linear recurrences with constant coefficients, signature (15).

Formula

a(n) = A067417(n+4, 4).

a(n) = 7*(3*5)^(n-1), n >= 1, a(0)=1.

G.f.: (1-8*x)/(1-15*x).

Prog

(Magma) [Ceiling(7*(3*5)^(n-1)): n in [0..20]]; // Vincenzo Librandi, Oct 02 2011

Crossrefs

Cf. A067419 (fourth column), A067421 (sixth column), A001024 (powers of 15).

Sequence in context: A093741 A139742 A120049 * A368351 A358957 A131869

Adjacent sequences: A067417 A067418 A067419 * A067421 A067422 A067423

Keyword

nonn,easy

Author

Wolfdieter Lang, Jan 25 2002

Status

approved