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%I #11 Mar 12 2017 16:17:52
%S 1,31,37,43,46,61,67,73,79,85,91,106,109,121,127,133,136,145,151,157,
%T 166,169,181,199,211,217,226,232,235,241,253,265,271,274,277,289,295,
%U 301,307,313,316,325,331,337,343,361,379,391,397,406,409,421,433,451,463,469,481,496,505,511
%N Numbers that are centered k-gonal numbers for three or more values of k.
%C Numbers satisfying 1 + n*m*(m+1)/2 for three or more values of (n,m), where n >= 0 m > 1.
%C Numbers in this sequence appear in A101321 at least four times (because the second column contains every positive integer).
%H Daniel Sterman, <a href="/A279846/b279846.txt">Table of n, a(n) for a(n)<1000</a>
%e 109 is in the sequence because 109 is a centered triangular number, a centered 18-gonal number, and a centered 36-gonal number.
%Y Cf. A062712 (rough equivalent for polygonal numbers).
%Y Cf. A101321 (table of all centered polygonal numbers).
%Y Cf. A275340 (list of nontrivial centered polygonal numbers).
%K nonn
%O 1,2
%A _Daniel Sterman_, Dec 20 2016
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