A069559 - OEIS

%I #9 Sep 19 2024 21:42:40

%S 1,3,6,15,21,28,45,66,325,666,946,1128,1326,2145,2346,2628,2926,4186,

%T 8128,8385,8646,8911,11325,11628,14365,18145,18915,51681,52326,54615,

%U 54946,58311,111628,118341,152628,214185,258121,614386,1152921,1211346

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

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

%e 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.

%Y Intersection of A000217 and A069570.

%Y Cf. A069556, A069557, A069558.

%K base,nonn

%O 1,2

%A _Amarnath Murthy_, Mar 22 2002

%E More terms from _Sascha Kurz_, Mar 23 2002

%E Offset changed by _Andrew Howroyd_, Sep 19 2024