A005055 a(n) = 7*5^n.

7, 35, 175, 875, 4375, 21875, 109375, 546875, 2734375, 13671875, 68359375, 341796875, 1708984375, 8544921875, 42724609375, 213623046875, 1068115234375, 5340576171875, 26702880859375, 133514404296875, 667572021484375, 3337860107421875, 16689300537109375

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Comments

a(n) = sum of row n+1 of triangle A249307. - Reinhard Zumkeller, Nov 14 2014

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Tanya Khovanova, Recursive Sequences
• Index entries for linear recurrences with constant coefficients, signature (5).

Crossrefs

Cf. A000351.

Programs

Haskell

a005055 = (* 7) . (5 ^)
a005055_list = iterate (* 5) 7  -- Reinhard Zumkeller, Nov 14 2014

Magma

[7*5^n: n in [0..20]]; // Vincenzo Librandi, Sep 15 2011

Mathematica

7*5^Range[0, 100] (* Vladimir Joseph Stephan Orlovsky, Jun 09 2011 *)
NestList[5#&,7,30] (* Harvey P. Dale, Sep 28 2015 *)

Formula

a(n) = 5*a(n-1), n>0; a(0)=7. G.f.: 7/(1-5*x). - Philippe Deléham, Nov 23 2008

E.g.f.: 7*e^(5*x). - Mohammad K. Azarian, Jan 15 2009