OFFSET
1,1
EXAMPLE
36 is a term being a power (36=6^2) and an abundant number as a multiple of 6.
MAPLE
N:= 20000: # to get terms <= N
isab:= proc(n) local F, t;
F:= ifactors(n)[2];
mul((t[1]^(t[2]+1)-1)/(t[1]-1), t = F) > 2*n
end proc:
S:= select(isab, {seq(seq(x^i, i=2..ilog[x](N)), x=2..isqrt(N))}):
sort(convert(S, list)); # Robert Israel, Sep 12 2024
MATHEMATICA
Select[Range[2*10^4], DivisorSigma[1, #]-2#>0&&GCD@@FactorInteger[#][[All, 2]]>1&]
PROG
(PARI) ok(n)=sigma(n)-2*n>0 && ispower(n)
CROSSREFS
KEYWORD
nonn
AUTHOR
Waldemar Puszkarz, Sep 11 2024
STATUS
approved