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 A265641 #20 Jan 23 2019 08:38:27 %S A265641 1,2,3,4,5,7,8,9,11,44,99,101,121,131,151,171,181,191,212,242,252,272, %T A265641 292,313,333,343,353,363,373,383,404,464,484,575,656,676,727,747,757, %U A265641 787,797,828,848,909,919,929,1331,5445,6336,8228 %N A265641 Palindromes in base 10 (A002113) which are also prime factorization palindromes (A265640). %C A265641 Composite numbers in the sequence have two forms of symmetry. %H A265641 David A. Corneth, <a href="/A265641/b265641.txt">Table of n, a(n) for n = 1..10000</a> %H A265641 David A. Corneth, <a href="/A265641/a265641_1.gp.txt">n, a(n), symmetric factorization of a(n)</a> %H A265641 David A. Corneth, <a href="/A265641/a265641_2.gp.txt">PARI program</a> %e A265641 5445 = 3*11*5*11*3, so it is a term. %o A265641 (PARI) isok(n) = (Vecrev(m=digits(n))==m) && (isprime(core(n)) || issquare(n)); \\ _Michel Marcus_, Jan 15 2019 %o A265641 (PARI) \\ See Corneth link \\ _David A. Corneth_, Jan 22 2019 %Y A265641 Intersection of A002113 and A265640. %K A265641 nonn,base %O A265641 1,2 %A A265641 _Vladimir Shevelev_, Dec 11 2015 %E A265641 Missing term 8 inserted by _Martin Schlegel_, Jan 15 2019