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 A086064 #8 Feb 23 2025 09:25:35 %S A086064 2,10,6,10,6,3,6,10,6,10,10,10,10,10,10,10,10,10,10,10,6,10,10,10,10, %T A086064 5,10,10,10,10,10,10,10,10,10,10,10,10,10,10,6,10,10,10,10,10,10,10, %U A086064 10,10,3,10,10,10,10,10,10,10,10,10,6,10,10,10,10,10,10,10,10,10,10 %N A086064 In decimal representation: smallest k>1 such that n is a substring of n*k. %C A086064 1 < a(n) <= 10; 4, 7 and 8 do not occur. %F A086064 a(n) = A087217(n)/n for n>0. - _Reinhard Zumkeller_, Aug 26 2003 %o A086064 (Python) %o A086064 def a(n): %o A086064 s = str(n) %o A086064 return next(k for k in range(2, 11) if s in str(n*k)) %o A086064 print([a(n) for n in range(71)]) # _Michael S. Branicky_, Feb 23 2025 %Y A086064 Cf. A045537. %K A086064 nonn,base %O A086064 0,1 %A A086064 _Reinhard Zumkeller_, Aug 24 2003