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 A038494 Images of hexamorphic numbers: suppose k-th hexagonal number H(k) (A000384) ends in k; sequence gives positive values of H(k). 1
 1, 45, 66, 1225, 1326, 4950, 5151, 11175, 11476, 31125, 282376, 499500, 501501, 780625, 1533876, 38294376, 49995000, 50015001, 63275625, 175809376, 3300740625, 4999950000, 5000150001, 7050959376, 16425690625, 23926109376 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Book, p. 104. C. Pickover, Computers and Imagination, 1991. 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. LINKS EXAMPLE 45 is included because it is the 5th hexagonal number and it ends in 5. MATHEMATICA Select[Array[{PolygonalNumber[6, #], #} &, 10^6], FromDigits[Take[IntegerDigits[#], -IntegerLength@ #2]] == #2 & @@ # &][[All, 1]] (* Michael De Vlieger, Jun 30 2018 *) PROG (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 CROSSREFS Cf. A039594, A000384. Sequence in context: A046426 A056776 A172466 * A026043 A053720 A259218 Adjacent sequences:  A038491 A038492 A038493 * A038495 A038496 A038497 KEYWORD nonn,base AUTHOR EXTENSIONS More terms from Patrick De Geest, Jun 15 1999 Name corrected by Robert Dawson, Jun 20 2018 STATUS approved

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Last modified March 26 18:36 EDT 2019. Contains 321511 sequences. (Running on oeis4.)