# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a232820 Showing 1-1 of 1 %I A232820 #15 Nov 14 2014 13:20:50 %S A232820 1,18,144,0,-28200,-814968,-15203328,0,16696909080,893794451000, %T A232820 25789252433472,0,-54804262577596532,-4044941639317807200, %U A232820 -161017938434267136000,0,621130358284578576358416,59512584052525004199214632,3008072527724272784969384000,0 %N A232820 Imaginary part of the sum over the n-th powers of all Gaussian integers in the n X n base square in the first quadrant. %H A232820 Colin Barker, Table of n, a(n) for n = 1..200 %F A232820 Conjecture: a(4n) = 0. - _Michel Marcus_, Nov 09 2014 %t A232820 g[n_] := Sum[(a + b I)^n, {a, 1, n}, {b, 1, n}]; Table[Im[g[n]], {n, 33}] %o A232820 (PARI) vector(100, n, imag(sum(x=1, n, sum(y=1, n, (x+I*y)^n)))) \\ _Colin Barker_, Nov 09 2014 %Y A232820 Cf. A230308-A230310, A073763, A232819. %K A232820 sign %O A232820 1,2 %A A232820 _José María Grau Ribas_, Nov 30 2013 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE