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

Author

Wolfdieter Lang, Jan 25 2002

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..800
• Index entries for linear recurrences with constant coefficients, signature (15).

Crossrefs

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

Programs

Magma

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

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).