login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A260934
Sum of evil divisors of n. For evil numbers see A001969.
2
0, 0, 3, 0, 5, 9, 0, 0, 12, 15, 0, 21, 0, 0, 23, 0, 17, 36, 0, 35, 3, 0, 23, 45, 5, 0, 39, 0, 29, 69, 0, 0, 36, 51, 5, 84, 0, 0, 42, 75, 0, 9, 43, 0, 77, 69, 0, 93, 0, 15, 71, 0, 53, 117, 5, 0, 60, 87, 0, 161, 0, 0, 75, 0, 70
OFFSET
1,3
COMMENTS
a(n) = 0 if there is no evil divisor.
LINKS
FORMULA
a(n) = A000203(n) - A227873(n). - Vladimir Shevelev, Oct 25 2013.
EXAMPLE
a(6) = A000203(6) - A227873(6) = 12 - 3 = 9.
MATHEMATICA
Total[Select[Divisors@ #, EvenQ@ First@ DigitCount[#, 2] &]] & /@ Range@ 65 (* Michael De Vlieger, Aug 04 2015 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
Edited by Wolfdieter Lang, Aug 23 2015
STATUS
approved