OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MAPLE
isA188629 := proc(n) if numtheory[tau](n^2) = numtheory[tau](n^2-1)+1 then true; else false; end if; end proc:
for n from 1 do if isA188629(n) then print(n) ; end if; end do: # R. J. Mathar, Apr 14 2011
MATHEMATICA
Select[Range[10000], DivisorSigma[0, #^2 - 1] + 1 == DivisorSigma[0, #^2] &]
PROG
(PARI) is(k) = k > 1 && numdiv(k^2-1) + 1 == numdiv(k^2); \\ Amiram Eldar, Apr 17 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Apr 06 2011
STATUS
approved