A220103 Triangular numbers that are also Jacobsthal numbers (A001045).

0, 1, 3, 21, 171

Offset

1,3

Links

Table of n, a(n) for n=1..5.

Thomas Koshy and Zhenguang Gao, Triangular Numbers in the Jacobsthal Family, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 12, Paper A64, 2012.

Crossrefs

Cf. A000217, A001045.

Sequence in context: A214391 A370284 A046637 * A132805 A372459 A189475

Adjacent sequences: A220100 A220101 A220102 * A220104 A220105 A220106

Keyword

nonn,fini,full

Author

Eric M. Schmidt, Dec 04 2012

Status

approved