A069700 Triangular numbers with internal digits 9.

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 190, 496, 595, 990, 5995

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]] == {9}, Print[n(n + 1)/2]], {n, 14, 10^6}]

Crossrefs

Cf. A069675 to A069684, A069693 to A069700.

Sequence in context: A069699 A213516 A078254 * A069698 A069696 A025724

Adjacent sequences: A069697 A069698 A069699 * A069701 A069702 A069703

Keyword

fini,full,nonn,base

Author

Amarnath Murthy, Apr 06 2002

Status

approved