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 A164768 #8 Feb 08 2020 04:07:06 %S A164768 1,2,1,3,2,6,4,5,7,8,10,14,16,20,25,3,32,40,50,6,64,80,100,12,113,15, %T A164768 160,200,24,226,30,320,400,48,452,60,565,75,800,96,904,120,1130,150, %U A164768 1600,192,1808,240,2260,300,2825,375,384,3616,480,4520,600,5650 %N A164768 First differences of A003592. %C A164768 The gaps between the natural numbers whose reciprocals are terminating decimals. %H A164768 Amiram Eldar, <a href="/A164768/b164768.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..312 from Barry Wells) %F A164768 a(n) = A003592(n+1) - A003592(n). - _Amiram Eldar_, Feb 08 2020 %e A164768 The first few terms of A003592 are 1, 2, 4, 5, 8, 10, 16 because 1/1, 1/2, 1,4, 1/5, 1/8 etc. terminate and 1/3, 1/6, 1/7, 1/9 etc. repeat. Hence the denominators of the first few terminating decimals are 1, 2, 4, 5, 8, 10, 16 and the first differences between these gives the sequence 1,2,1,3,2,4 %Y A164768 Cf. A003592. %K A164768 nonn %O A164768 1,2 %A A164768 Barry Wells (wells.barry(AT)gmail.com), Aug 26 2009, Sep 24 2009