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A307348
Numbers k such that there are no palindromic triangular numbers of length k.
2
OFFSET
1,1
LINKS
P. De Geest, Palindromic Squares
Eric Weisstein's World of Mathematics, Palindromic Number
MATHEMATICA
A003098 = Select[PolygonalNumber[3, Range[0, 10^6]], PalindromeQ];
(* Set Range to level of desired running time. *)
nopal[n_] := Length[Select[A003098, IntegerLength[#] == n || (n == 1 && # == 0) &]]; Select[Range[12], nopal[#] == 0 &]
(* Set Range to encompass length of last value in A003098. *)
CROSSREFS
KEYWORD
nonn,base,hard,more
AUTHOR
Robert Price, May 01 2019
STATUS
approved