A069559 Triangular numbers in which the k-th significant digit either divides k or is a multiple of k.

1, 3, 6, 15, 21, 28, 45, 66, 325, 666, 946, 1128, 1326, 2145, 2346, 2628, 2926, 4186, 8128, 8385, 8646, 8911, 11325, 11628, 14365, 18145, 18915, 51681, 52326, 54615, 54946, 58311, 111628, 118341, 152628, 214185, 258121, 614386, 1152921, 1211346

Offset: 1

Author

Amarnath Murthy, Mar 22 2002

Keywords

• base
• nonn

Comments

If the smallest prime divisor of n is > 7 then the n-th digit is 1.

Examples

			8646 is a member in which the fourth digit is 8 a multiple of 4, the third one is 6 a multiple of 3, the second one is 4 a multiple of 2 and the least significant digit is 6.
		

Crossrefs

Intersection of A000217 and A069570.

Cf. A069556, A069557, A069558.

Extensions

More terms from Sascha Kurz, Mar 23 2002

Offset changed by Andrew Howroyd, Sep 19 2024