OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
MATHEMATICA
FactorInteger[#][[1, 1]] & /@ Select[Range@ 250, Function[n, Or[n == 1, And[Length@ # == 1, EvenQ@ First@ #], And[Length@ # == 2, SameQ @@ #]] &[FactorInteger[n][[All, -1]]]]] (* Michael De Vlieger, Mar 04 2017 *)
PROG
(PARI) is(n)=my(f=factor(n)[, 2]); #f==0 || (#f==2 && f[1]==f[2]) || (#f==1 && f[1]%2==0);
spf(n) = if (n==1, 1, factor(n)[1, 1]);
lista(nn) = {for (n=1, nn, if (is(n), print1(spf(n), ", ")); ); } \\ Michel Marcus, Mar 04 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Sep 06 2006
EXTENSIONS
More terms from Michel Marcus, Mar 04 2017
STATUS
approved