A386549 Indices of hexagonal numbers that are one-sixth of another hexagonal number.
0, 1, 72, 7031, 688942, 67509261, 6615218612, 648223914691, 63519328421082, 6224245961351321, 609912584884008352, 59765209072671467151, 5856380576536919772422, 573865531291545466230181, 56232965685994918770785292, 5510256771696210494070728411, 539948930660542633500160598962
Offset: 1
Examples
72 is in this sequence because the 72th hexagonal number (10296) is one-sixth of another hexagonal number.
Links
- Index entries for linear recurrences with constant coefficients, signature (99,-99,1).
Formula
G.f.: x^2 * (1 - 27*x + 2*x^2) / (1 - 99*x + 99*x^2 - x^3). - Jinyuan Wang, Jul 26 2025
Extensions
More terms from Jinyuan Wang, Jul 26 2025