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 A243118 #4 May 30 2014 01:04:38 %S A243118 2,4,5,7,9,10,11,16,17,19,21,22,23,25,26,27,29,33,34,35,37,41,43,45, %T A243118 46,47,49,50,51,52,53,55,58,59,61,64,65,66,67,69,70,71,73,75,76,77,79, %U A243118 81,82,83,85,86,87,88,89,92,94,95,97,99,100,101,103,105,106 %N A243118 Numbers n such that A242962(x) = n has no solution. %C A243118 A242962(n) = (n*(n+1)/2) mod antisigma(n) = A000217(n) mod A024816(n); where A000217(n) = triangular numbers, A024816(n) = sum of numbers less than n which do not divide n. %C A243118 Union of A007369 and numbers 4 and 7. %C A243118 Complement of A243117. %C A243118 a(n) = A007369(n-2) for n >= 5, where A007369 = numbers n such that sigma(x) = n has no solution. %e A243118 4 is in the sequence because there is no x whose A242962(x) = 4. %Y A243118 Cf. A000203, A007369, A242962, A242963, A243117. %K A243118 nonn %O A243118 1,1 %A A243118 _Jaroslav Krizek_, May 29 2014