A069695 Triangular numbers with internal digits 3.

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 136, 231, 435, 630, 333336

Offset

1,3

Comments

For proof of finiteness see A069693.

Links

Table of n, a(n) for n=1..19.

Mathematica

Do[ If[ Union[ Drop[ RotateLeft[ IntegerDigits[n(n + 1)/2]], -2]] == {3}, Print[n(n + 1)/2]], {n, 14, 2 10^6}]

Crossrefs

Cf. A069675 to A069684, A069693 to A069700.

Sequence in context: A077368 A069693 A069694 * A069697 A069699 A213516

Adjacent sequences: A069692 A069693 A069694 * A069696 A069697 A069698

Keyword

fini,full,nonn,base

Author

Amarnath Murthy, Apr 06 2002

Extensions

Extended by Robert G. Wilson v, Apr 07 2002

Status

approved