OFFSET
1,2
COMMENTS
a(n) is divisible by A026741(n). - Robert Israel, Oct 01 2017
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
EXAMPLE
12 is divisible by 2 and 3. The positive integers which are <= 12 and which are divisible by 2 or 3 but not by both 2 and 3 are: 2, 3, 4, 8, 9, 10. a(12) = the sum of these integers, which is 36.
MAPLE
f:= proc(n) local P;
P:= convert(numtheory:-factorset(n), list);
convert(select(k -> nops(select(p->k mod p = 0, P))=1, [$2..n]), `+`)
end proc:
1, seq(f(n), n=2..100); # Robert Israel, Oct 01 2017
MATHEMATICA
Table[Total@ Select[Range@ n, Function[k, Total@ Boole@ Map[Divisible[k, #] &, FactorInteger[n][[All, 1]]] == 1]], {n, 62}] (* Michael De Vlieger, Oct 01 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jul 30 2006
EXTENSIONS
Corrected and extended by Joshua Zucker, Aug 12 2006
STATUS
approved