OFFSET
1,1
COMMENTS
1/k + Sum_{p|k} 1/p = 1 when k is a primary pseudoperfect number (A054377).
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
MATHEMATICA
fa=FactorInteger; A[n_] := Sum[1/fa[n][[i, 1]], {i, Length@fa@n}]; Select[1 + Range@1200, A[#] + 1/# > 1 &]
PROG
(PARI) is(n)=my(t=1-1/n); forprime(p=2, 97, if(n%p==0, n/=p^valuation(n, p); t-=1/p; if(t<0, return(1)))); if(n<101^ceil(101*t), return(0)); my(f=factor(n)[, 1]); t<sum(i=1, #f, 1/f[i]) \\ Charles R Greathouse IV, Dec 27 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
José María Grau Ribas, Jun 23 2013
STATUS
approved