This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A353439 #12 Jul 01 2023 16:54:07 %S A353439 3,12,13,17,19,23,26,27,28,29,30,31,32,33,34,38,41,42,43,46,47,48,49, %T A353439 51,52,53,57,58,59,61,62,63,65,67,68,69,71,72,73,74,75,76,81,83,85,87, %U A353439 88,89,92,93,94,95,97,98,102,103,104,105,106,107,109,113,114,115,116 %N A353439 Integers m such that the decimal expansion of 1/m contains the digit 3. %C A353439 If m is a term, 10*m is also a term, so terms with no trailing zeros are all primitive terms. %e A353439 m = 12 is a term since 1/12 = 0.083333333333... (here, 3 is the smallest digit). %e A353439 m = 13 is a term since 1/13 = 0.076923076923... %e A353439 m = 75 is a term since 1/15 = 0.013333333333... (here, 3 is the largest digit). %t A353439 f[n_] := Union[ Flatten[ RealDigits[ 1/n][[1]] ]]; Select[ Range@ 125, MemberQ[f@#, 3] &] %Y A353439 A350814 (largest digit=3) and A352157 (smallest digit=3) are subsequences. %Y A353439 Similar with digit k: A352154 (k=0), A353437 (k=1), A353438 (k=2), this sequence (k=3), A353440 (k=4), A353441 (k=5), A353442 (k=6), A353443 (k=7), A353444 (k=8), A333237 (k=9). %K A353439 nonn,base %O A353439 1,1 %A A353439 _Bernard Schott_ and _Robert G. Wilson v_, Apr 22 2022