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Numbers k such that k*(3k-1)/2 is a pentagonal palindrome.
4

%I #11 Aug 11 2024 14:41:29

%S 1,2,4,26,44,101,693,2173,2229,4228,6010,26466,26906,31926,44059,

%T 1258723,1965117,1979130,2684561,13280839,59401650,84885761,100058581,

%U 225563533,316882086,700457153,818049201,851649306,1345679688

%N Numbers k such that k*(3k-1)/2 is a pentagonal palindrome.

%H P. De Geest, <a href="https://www.worldofnumbers.com/penta.htm">Palindromic Pentagonals</a>

%Y Cf. A002069, A000326.

%K nonn,base

%O 1,2

%A _Patrick De Geest_

%E More terms from _Patrick De Geest_, Nov 15 1998