cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A173657 2+2^n+3^n.

Original entry on oeis.org

4, 7, 15, 37, 99, 277, 795, 2317, 6819, 20197, 60075, 179197, 535539, 1602517, 4799355, 14381677, 43112259, 129271237, 387682635, 1162785757, 3487832979, 10462450357, 31385253915, 94151567437, 282446313699, 847322163877, 2541932937195, 7625731702717
Offset: 0

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Author

Gary Detlefs, Nov 24 2010

Keywords

Comments

Sum of the n-th powers of the first 5 Fibonacci numbers A000045(0..4).

Crossrefs

Cf. A075996 (primes), A007689.

Programs

  • Maple
    with(combinat):f:=n-> sum(fibonacci(k)^n,k=0..4):seq(f(n),n=1..20);
  • Mathematica
    Table[2+2^n+3^n,{n,0,40}] (* or *) LinearRecurrence[{6,-11,6},{4,7,15},40](* Harvey P. Dale, Jun 08 2011 *)

Formula

a(n)= 6*a(n-1)-11*a(n-2)+6*a(n-3).
a(n) = 1+A001550(n).
G.f.: ( -4+17*x-17*x^2 ) / ( (x-1)*(3*x-1)*(2*x-1) ).

Extensions

More terms from Harvey P. Dale, Jun 08 2011