A179267 Numbers n which divide the periodic part (with zeros at end) of the decimal expansion of 1/n.

3, 6, 487, 974, 1461, 2435, 2922, 4383, 4870, 7305, 8766, 12175, 13149, 14610, 17532, 21915, 24350, 26298, 29220, 36525, 43830, 48700, 52596, 65745, 73050, 87660, 109575, 131490, 146100, 219150, 262980, 328725, 438300, 657450, 1095750

Offset: 1

Author

T. D. Noe, Jul 06 2010

Keywords

• base
• nonn

Comments

There are two definitions of the periodic part: zeros may either begin or end the periodic part. For example, for 1/11 = 0.0909090..., the periodic part could be either 09 or 90. This sequences assumes that the zeros are at the end of the periodic part. See A171928 for the case of zeros at the beginning of the periodic part.

Note that the terms following 487 are divisible by 487. This pattern continues until the prime number 56598313, which is another member of A045616.

Programs

Mathematica

Reap[Do[k=RealDigits[1/n][[1,-1]]; If[Head[k] === List && Mod[FromDigits[k],n] == 0, Sow[n]], {n,10000}]][[2,1]]