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 A272637 #6 Mar 07 2024 13:59:09 %S A272637 1,83,21,26,47,73,30,103,133,59,3,62,65,127,3,130,133,263,11,274,285, %T A272637 559,211,770,109,879,247,1126,1373,51,89,35,31,66,97,163,65,57,122, %U A272637 179,301,30,331,1,83,21,26,47,73,30,103,133,59,3,62,65,127,3,130,133,263,11,274,285,559,211,770,109,879,247,1126,1373,51,89,35,31,66,97,163,65,57,122,179,301,30,331 %N A272637 a(1)=1, a(2)=82; thereafter a(n) = squarefree part of a(n-1)+a(n-2). %C A272637 Periodic with period length 43. The period is [1, 83, 21, 26, 47, 73, 30, 103, 133, 59, 3, 62, 65, 127, 3, 130, 133, 263, 11, 274, 285, 559, 211, 770, 109, 879, 247, 1126, 1373, 51, 89, 35, 31, 66, 97, 163, 65, 57, 122, 179, 301, 30, 331]. %D A272637 Fred W. Helenius, Posting to Math Fun Mailing List, May 06 2016 %H A272637 <a href="/index/Rec#order_43">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1). %Y A272637 Cf. A272636. %K A272637 nonn %O A272637 1,2 %A A272637 _N. J. A. Sloane_, May 05 2016