This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A283550 #23 Mar 27 2017 19:41:17 %S A283550 1,2,3,4,5,6,7,8,9,10,11,13,14,15,16,17,19,21,22,23,25,26,27,28,29,31, %T A283550 33,34,35,37,39,41,43,45,46,47,49,51,53,55,57,59,61,63,65,67,69,71,73, %U A283550 75,77,79,81,83,85,87,89,91,93,95,97,99,101,103,105,107 %N A283550 Numbers that are not the sum of abundant numbers (not necessarily distinct). %C A283550 a(496) = 991 is the last term. %C A283550 Subsequence of A048242 (Numbers that are not the sum of two abundant numbers). %C A283550 Giovanni Resta noticed that 991 is the largest number that is not a sum of abundant numbers. %H A283550 Amiram Eldar, <a href="/A283550/b283550.txt">Table of n, a(n) for n = 1..496</a> %H A283550 Giovanni Resta, <a href="http://www.numbersaplenty.com/set/abundant_number/">abundant numbers</a> %e A283550 20161 = 12 + 304 + 19845 is the sum of 3 abundant numbers and thus not in the sequence (although it is in A048242, since it is not the sum of 2 abundant numbers). %t A283550 AbundantQ[n_] := DivisorSigma[1, n] > 2 n; a = Select[Range[1000], AbundantQ[#] &]; nn = Dimensions[a][[1]]; t = Rest[CoefficientList[ Series[Product[(1 + x^a[[k]]), {k, nn}], {x, 0, a[[-1]]}], x]]; f = Flatten[Position[t, 0]] %Y A283550 Cf. A271113, A048242, A005101. %K A283550 nonn,fini,full %O A283550 1,2 %A A283550 _Amiram Eldar_, Mar 10 2017