OFFSET
1,1
EXAMPLE
The sum of the prime factors of 90 = 2 * 3^2 * 5 is 2 + 3 + 5 = 10; the sum of the prime factors of 91 = 7 * 13 = 20. Hence 90 belongs to the sequence.
MATHEMATICA
p[n_] := Apply[Plus, Transpose[FactorInteger[n]][[1]]]; Select[Range[2, 10^5], 2*p[ # ] == p[ # + 1] &]
PROG
(PARI) is(k) = 2*vecsum(factor(k)[, 1]) == vecsum(factor(k+1)[, 1]); \\ Jinyuan Wang, Jan 15 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Oct 18 2002
EXTENSIONS
Offset changed to 1 and more terms from Jinyuan Wang, Jan 15 2022
STATUS
approved