A077368 Triangular numbers whose external digits as well as internal digits form triangular numbers.

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 231, 435, 465, 666, 1035, 2211, 3916, 4005, 6216, 6786, 19900, 41905, 46665, 48205, 162165, 171405, 200661, 222111, 329266, 400065, 1057785, 1646205, 2003001, 2318781, 2943951, 10628355

Offset

0,3

Comments

Common members of A077366 and A077367.

Links

Table of n, a(n) for n=0..40.

Crossrefs

Cf. A077366, A077367.

Sequence in context: A025731 A077367 A077366 * A069693 A069694 A069695

Adjacent sequences: A077365 A077366 A077367 * A077369 A077370 A077371

Keyword

base,easy,nonn

Author

Amarnath Murthy, Nov 06 2002

Extensions

Extended by Ray Chandler, Feb 28 2007

Status

approved