A353440 Integers m such that the decimal expansion of 1/m contains the digit 4.

7, 14, 17, 19, 21, 22, 23, 24, 25, 26, 28, 29, 31, 34, 35, 38, 39, 41, 43, 46, 47, 49, 51, 53, 56, 57, 58, 59, 61, 62, 65, 67, 68, 69, 70, 71, 76, 79, 81, 83, 84, 85, 86, 87, 89, 92, 93, 94, 95, 96, 97, 98, 102, 103, 104, 106, 107, 109, 112, 113, 114, 115, 116, 117, 118

Offset: 1

Author

Bernard Schott and Robert G. Wilson v, Apr 24 2022

Keywords

• nonn
• base

Comments

If m is a term, 10*m is also a term, so terms with no trailing zeros are all primitive terms.

Examples

			m = 14 is a term since 1/14 = 0.0714285714285...
m = 22 is a term since 1/22 = 0.04545454545... (here, 4 is the smallest digit).
m = 693 is a term since 1/693 = 0.001443001443... (here, 4 is the largest digit).
		

Links

• Index entries for sequences related to decimal expansion of 1/n.

Crossrefs

A351470 (largest digit=4) and A352158 (smallest digit=4) are subsequences.

Similar with digit k: A352154 (k=0), A353437 (k=1), A353438 (k=2), A353439 (k=3), this sequence (k=4), A353441 (k=5), A353442 (k=6), A353443 (k=7), A353444 (k=8), A333237 (k=9).

Programs

Mathematica

f[n_] := Union[ Flatten[ RealDigits[ 1/n][[1]] ]]; Select[ Range@ 125, MemberQ[f@#, 4] &]