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 A083477 #17 Jul 13 2024 02:12:45 %S A083477 2,3,4,5,6,7,8,9,55,111,111,232,353,111,595,232,353,595,10101,1111, %T A083477 606,525,424,303,323,343,363,383,10101,10601,1111,929,727,505,525,545, %U A083477 565,585,12121,12521,12921,2332,273372,707,727,747,767,787,10101,12421 %N A083477 Smallest palindrome > 1 and == 1 (mod n-th palindrome). %H A083477 Chai Wah Wu, <a href="/A083477/b083477.txt">Table of n, a(n) for n = 1..208</a> %e A083477 a(11) = 111 because A002113(11) = 22 and 111 = 5*22+1. %o A083477 (Python) %o A083477 from itertools import count %o A083477 def A083477(n): %o A083477 if n==1: return 2 %o A083477 q =(c:=n+1-x)*x+int(str(c)[-2::-1] or 0) if n+1<(x:=10**(len(str(n+1>>1))-1))+(y:=10*x) else (c:=n+1-y)*y+int(str(c)[::-1] or 0) %o A083477 for k in count(n+2): %o A083477 if (p:=int((c:=k-x)*x+int(str(c)[-2::-1] or 0) if k<(x:=10**(len(str(k>>1))-1))+(y:=10*x) else (c:=k-y)*y+int(str(c)[::-1] or 0)))%q==1: %o A083477 return p # _Chai Wah Wu_, Jul 12 2024 %Y A083477 Cf. A083478. %K A083477 base,nonn %O A083477 1,1 %A A083477 _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 03 2003 %E A083477 Corrected and extended by _David Wasserman_, Nov 16 2004