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 A020485 #29 Jan 05 2025 19:51:34 %S A020485 0,1,2,3,4,5,6,7,8,9,0,11,252,494,252,525,272,272,252,171,0,252,22, %T A020485 161,696,525,494,999,252,232,0,434,2112,33,272,525,252,111,494,585,0, %U A020485 656,252,989,44,585,414,141,2112,343,0,969,676,212,27972,55,616,171,232,767,0,26962 %N A020485 Least positive palindromic multiple of n, or 0 if none exists. %C A020485 Smallest positive palindrome divisible by n, or 0 if no such palindrome exists (which happens iff n is a multiple of 10). - _N. J. A. Sloane_, Apr 04 2019 %C A020485 The existence of palindromic multiples is a corollary of the theorem that an arithmetic progression with initial term c and a positive common difference d contains infinitely many palindromic numbers unless both of these numbers are multiples of 10. - M. Harminc (harminc(AT)duro.science.upjs.sk), Jul 14 2000 %H A020485 Giovanni Resta, <a href="/A020485/b020485.txt">Table of n, a(n) for n = 0..10000</a> (first 8181 terms from N. J. A. Sloane) %H A020485 Ely Golden, <a href="/A020485/a020485_1.py.txt">Python program for generating terms of this sequence</a> %H A020485 M. Harminc and R. Sotak, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/36-3/harminc.pdf">Palindromic numbers in arithmetic progressions</a>, Fibonacci Quarterly Journal, Jun-Jul (1998), pp. 259-262. %F A020485 a(n) = n*A050782(n). - _Michel Marcus_, Jan 22 2019 %Y A020485 Cf. A002113, A050782. %K A020485 nonn,base %O A020485 0,3 %A A020485 _David W. Wilson_ %E A020485 a(0)=0 added by _N. J. A. Sloane_, Apr 04 2019