A318939 - OEIS

A318939

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

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

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..28.

P. J. C. Lamont, The number of Cayley integers of given norm, Proceedings of the Edinburgh Mathematical Society, 25.1 (1982): 101-103. See (10).

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)];

PROG

(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

CROSSREFS

Cf. A318935, A318938.

Sequence in context: A158374 A349031 A006912 * A223215 A057012 A115484

Adjacent sequences: A318936 A318937 A318938 * A318940 A318941 A318942

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 15 2018

STATUS

approved