# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a050455 Showing 1-1 of 1 %I A050455 #10 Dec 06 2018 07:52:30 %S A050455 0,0,81,0,0,81,2401,0,81,0,14641,81,0,2401,50706,0,0,81,130321,0,2482, %T A050455 14641,279841,81,0,0,531522,2401,0,50706,923521,0,14722,0,1503026,81, %U A050455 0,130321,2313522,0,0,2482,3418801,14641,50706,279841 %N A050455 a(n) = Sum_{d|n, d=3 mod 4} d^4. %H A050455 Seiichi Manyama, Table of n, a(n) for n = 1..10000 %t A050455 a[n_] := DivisorSum[n, #^4 &, Mod[#, 4]==3 &]; Array[a, 30] (* _Amiram Eldar_, Dec 06 2018 *) %K A050455 nonn %O A050455 1,3 %A A050455 _N. J. A. Sloane_, Dec 23 1999 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE