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.

A034665 Sum of n-th powers of divisors of 32.

Original entry on oeis.org

6, 63, 1365, 37449, 1118481, 34636833, 1090785345, 34630287489, 1103823438081, 35253226045953, 1127000493261825, 36046397799139329, 1153203048319815681, 36897992296869404673, 1180663682709764194305
Offset: 0

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Crossrefs

Programs

  • Magma
    [DivisorSigma(n,32): n in [0..15]]; // Vincenzo Librandi, Apr 17 2014
    
  • Mathematica
    Total[#^Range[0, 15]&/@Divisors[32]] (* Vincenzo Librandi, Apr 17 2014 *)
    LinearRecurrence[{63,-1302,11160,-41664,64512,-32768},{6,63,1365,37449,1118481,34636833},20] (* Harvey P. Dale, Jan 10 2015 *)
  • PARI
    a(n)=(64^n-1)/(2^n-1) \\ Charles R Greathouse IV, Oct 07 2015
    
  • Python
    print([1+2**n+4**n+8**n+16**n+32**n for n in range(15)]) # Karl V. Keller, Jr., Feb 02 2021
  • Sage
    [sigma(32,n)for n in range(0,15)] # Zerinvary Lajos, Jun 04 2009
    

Formula

G.f.: -3*(21504*x^5-27776*x^4+11160*x^3-1736*x^2+105*x-2) / ((x-1)*(2*x-1)*(4*x-1)*(8*x-1)*(16*x-1)*(32*x-1)). - Colin Barker, Apr 20 2014
a(n) = (2^(6*n) - 1)/( 2^n - 1). Exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + 63*x + 2667*x^2 + 97155*x^3 + ... is the o.g.f. for the 5th subdiagonal of triangle A022166, essentially A006110. - Peter Bala, Apr 07 2015
a(n) = 1 + 2^n + 4^n + 8^n + 16^n + 32^n for n>=0. - Karl V. Keller, Jr., Feb 02 2021