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 A330963 #7 Jan 05 2020 12:58:41 %S A330963 0,1,1,0,1,0,3,8,1,0,0,5,0,5,5,0,1,0,0,5,0,5,5,0,9,7,5,0,7,16,27,40,1, %T A330963 0,0,5,0,5,5,0,0,7,5,0,7,0,11,24,0,8,5,0,7,0,0,13,20,11,0,13,0,13,13, %U A330963 0,1,0,0,5,0,5,5,0,0,7,5,0,7,0,11,24,0,8,5 %N A330963 For any n >= 0: consider all pairs of numbers (x, y) whose binary representations can be interleaved (or shuffled) to produce the binary representation of n (possibly with leading zeros); a(n) is the least possible value of abs(x^2 - y^2). %H A330963 Rémy Sigrist, <a href="/A330963/a330963.txt">C program for A330963</a> %H A330963 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %e A330963 For n = 5: %e A330963 - the binary representation of 5 is "101", %e A330963 - the possible values for (x, y), restricted to x >= y without loss of generality, are: %e A330963 bin(5) x y |x^2-y^2| %e A330963 ------- - - --------- %e A330963 "101" 5 0 25 %e A330963 "1/01" 1 1 0 %e A330963 "10/1" 2 1 3 %e A330963 "1/0/1" 3 0 9 %e A330963 - hence a(5) = 0. %o A330963 (C) See Links section. %Y A330963 See A330925 for similar sequences. %Y A330963 Cf. A327195. %K A330963 nonn,base %O A330963 0,7 %A A330963 _Rémy Sigrist_, Jan 04 2020