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 A177202 #9 Sep 15 2013 00:56:02 %S A177202 1,2,3,4,5,7,8,11,13,14,17,19,23,26,29,31,37,38,41,43,47,53,59,61,62, %T A177202 67,71,73,74,77,79,83,86,89,97,101,103,107,109,113,119,122,127,131, %U A177202 134,137,139,143,146,149,151,157,158,161,163,167,173,179 %N A177202 Nontrivially polygonal-free numbers. %C A177202 Positive integers which are not multiples of any nontrivially polygonal numbers A090466. Generalization of squarefree numbers: numbers that are not divisible by a square greater than 1 (A005117) where "square" is replaced by triangular, square, pentagonal, hexagonal, and so forth. Positive integers which are not positive integer multiples of numbers in the array of A057145 below the second row (which has every positive integer) and right of the 2nd column (which has every positive integer). That is, positive integers which are not positive integer multiples of any triangular number >3, any square >4, any pentagonal number >5, any hexagonal number >6, any heptagonal number >7, any octagonal number >8, any 9-gonal (nonagonal) number >9 and so forth. Properly includes all primes. %F A177202 Complement of A177201. %Y A177202 Cf. A090466, A177201. %K A177202 easy,nonn %O A177202 1,2 %A A177202 _Jonathan Vos Post_, May 04 2010 %E A177202 Corrected and extended by _Sean A. Irvine_, Apr 09 2013