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 A064693 #6 Oct 03 2014 11:09:48 %S A064693 2,1,1,1,2,1,2,1,3,2,2,1,1,1,2,1,2,1,3,2,2,1,1,1,2,1,2,1,3,2,2,1,1,1, %T A064693 2,1,2,1,3,2,3,2,2,2,3,2,3,2,4,3,2,1,1,1,2,1,2,1,3,2,3,2,2,2,3,2,3,2, %U A064693 4,3,2,1,1,1,2,1,2,1,3,2,4,3,3,3,4,3,4,3,5,4,3,2,2,2,3,2,3,2,4,3,3,2,2,2,3 %N A064693 Number of connected components remaining when decimal expansion of the number n is cut from a piece of paper. %e A064693 We assume 1,2,3,5 have no hole; 0,4,6,9 have 1 hole; 8 has two holes. So cutting 8 from a piece of paper creates three connected components: one for each hole and one for the remainder of the paper. Hence a(8)=3. %Y A064693 Cf. A064531. Equals A064692 + 1. %K A064693 base,easy,nonn %O A064693 0,1 %A A064693 _Matthew Conroy_, Oct 11 2001