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%I #21 Jul 03 2018 05:36:36
%S 1,45,66,1225,1326,4950,5151,11175,11476,31125,282376,499500,501501,
%T 780625,1533876,38294376,49995000,50015001,63275625,175809376,
%U 3300740625,4999950000,5000150001,7050959376,16425690625,23926109376
%N Images of hexamorphic numbers: suppose k-th hexagonal number H(k) (A000384) ends in k; sequence gives positive values of H(k).
%D D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Book, p. 104.
%D C. Pickover, Computers and Imagination, 1991.
%D C. A. Pickover, Hexamorphic numbers, in Hexagonal cats Ch. 63 in Wonders of Numbers: Adventures in Mathematics, Mind, and Meaning, Oxford, England: Oxford University Press, pp. 154, 2001.
%e 45 is included because it is the 5th hexagonal number and it ends in 5.
%t Select[Array[{PolygonalNumber[6, #], #} &, 10^6], FromDigits[Take[IntegerDigits[#], -IntegerLength@ #2]] == #2 & @@ # &][[All, 1]] (* _Michael De Vlieger_, Jun 30 2018 *)
%o (PARI) lista(nn) = {for (n=1, nn, m = n*(2*n-1); if ((m - n) % 10^#Str(n) == 0, print1(m, ", ")););} \\ _Michel Marcus_, Sep 25 2015
%Y Cf. A039594, A000384.
%K nonn,base
%O 1,2
%A _Felice Russo_
%E More terms from _Patrick De Geest_, Jun 15 1999
%E Name corrected by _Robert Dawson_, Jun 20 2018