A060201 Images of centered hexamorphic numbers: suppose k-th centered hexagonal number H_c(k) (A003215) ends in k; sequence gives value of H_c(k).

1, 127, 817, 7651, 13267, 83167, 188251, 520417, 751501, 1332667, 1689751, 2519917, 4691251, 8331667, 75015001, 88015417, 117206251, 133326667, 325510417, 833316667, 7500150001, 9492356251, 10950460417

Offset

1,2

Comments

Note that all centered hexamorphic numbers end in the digits 1 and 7.

References

C. Pickover, Wonders of Numbers, Oxford University Press, NY, 2001, p. 152-155.

Links

Table of n, a(n) for n=1..23.

C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," Zentralblatt review

Example

127 is centered hexamorphic because it is the 7th centered hexagonal number and ends in 7. 817 is the 17th centered hexagonal and ends in 17.

Prog

(PARI) lista(nn) = {for (n=0, nn, my(m = 3*n*(n-1)+1); if ((m - n) % 10^#Str(n) == 0, print1(m, ", ")); ); } \\ Michel Marcus, Jun 21 2018

Crossrefs

Cf. A003215.

Sequence in context: A332574 A049202 A204737 * A140630 A183829 A168487

Adjacent sequences: A060198 A060199 A060200 * A060202 A060203 A060204

Keyword

base,nonn

Author

Jason Earls, Mar 18 2001

Status

approved