OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n=1..10000
EXAMPLE
n = 399 = sigma[14^2] = sigma[2*(11^2)] = 1+2+4+7+14+28+49+98+196 = 1+2+11+22+121+242; also sigma[42.42] = sigma[2.33.33] = sigma[1764] = sigma[2378] = 5187.
MATHEMATICA
Intersection[Table[DivisorSigma[1, w^2], {w, 1, 10000}], Table[DivisorSigma[1, 2*(w^2)], {w, 1, 10000}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Nov 19 2001
STATUS
approved