OFFSET
1,1
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000 (terms a(n) for n = 2..1002 from Harvey P. Dale).
EXAMPLE
646 = 2*17*19 so the sum of prime factors (with multiplicity) is 2+17+19 = 38 which is even and a divisor of 646 so 646 is in the sequence.
MATHEMATICA
dspfQ[n_]:=Module[{spf=Total[Times@@@FactorInteger[n]]}, EvenQ[spf] && Divisible[n, spf]]; Select[Range[4, 2500, 2], dspfQ] (* Harvey P. Dale, Oct 06 2011 *)
PROG
(PARI) is(n) = my(f = factor(n), s = sum(i = 1, #f~, f[i, 1] * f[i, 2])); s > 0 && s % 2 == 0 && n % s == 0 \\ David A. Corneth, Feb 07 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick De Geest, Dec 15 1998
EXTENSIONS
Offset corrected and a(1) = 2 added by Thomas Ordowski, Feb 07 2019
STATUS
approved