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.

A318939 If n=0 then 1 otherwise 48*(1+12*A318935(n))*(sum of cubes of odd divisors of n).

Original entry on oeis.org

1, 624, 5232, 17472, 42096, 78624, 146496, 214656, 337008, 472368, 659232, 831168, 1178688, 1371552, 1799808, 2201472, 2696304, 3066336, 3960624, 4280640, 5304096, 6010368, 6969024, 7592832, 9436224, 9828624, 11499936, 12754560, 14481024
Offset: 0

Views

Author

N. J. A. Sloane, Sep 15 2018

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory);
    A007814 := n -> padic[ordp](n, 2):
    T:= n -> add(2^(3*m),m=0..A007814(n));
    f := proc(n) local t2,i,d;
    if n=0 then return(1); fi;
    t2:=0; for d in divisors(n) do if (d mod 2) = 1 then t2:=t2+d^3; fi; od:
    48*(1+12*T(n))*t2;
    end;
    [seq(f(n),n=0..50)];
  • Python
    from sympy import divisor_sigma
    def A318939(n): return 3*(1+12*((1<<(3*(m:=(~n&n-1).bit_length())+3))-1)//7)*divisor_sigma(n>>m,3)<<4 if n else 1 # Chai Wah Wu, Jul 11 2022