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 A178654 #14 Apr 24 2022 02:29:40 %S A178654 727,10301,14341,16361,18181,30703,1003001,1145411,1163611,1201021, %T A178654 1363631,1452541,3001003,3425243,3503053,100030001,102343201, %U A178654 103212301,105272501,105343501,107070701,107121701,112030211,124525421,125010521 %N A178654 Palindromic primes of the form (q//R(q))/11 where q is an emirp, R() denotes digit-reversal and // concatenation. %C A178654 Concatenation of the emirps q (A006567) and their digit-reversed variant yields the sequence q//R(q) = 1331, 1771, 3113, 3773, 7117, 7337, 7997,.. %C A178654 Further division of each term through 11 (in the spirit of A132286) yields the sequence 121, 161, 283, 343, 647, 667, 727, 889, 9791.. %C A178654 If such a term is a palindromic prime (A002385), it joins the sequence. %C A178654 The sequence is generated by the emirps A006567(i) with i= 7, 10, 12, 14, 15, 17, 45, 59, 60, 63, 72, 77, 115, 139, 143, 280, 289,... %D A178654 M. Gardner: Mathematischer Zirkus, Seite 259 ff., Ullstein Berlin-Frankfurt/M.-Wien, 1988 %D A178654 W. Lietzmann: Sonderlinge im Reich der Zahlen, Duemmler, Bonn, 1948 %H A178654 Robert Israel, <a href="/A178654/b178654.txt">Table of n, a(n) for n = 1..2500</a> %H A178654 H. Gabai and D. Coogan, <a href="http://www.jstor.org/stable/2688705">On palindromes and palindromic primes</a>, Math. Mag. 42, pp. 252-254, 1969. %e A178654 79 = emirp(7), 97 = emirp(8), 7997 / 11 = 727 = palprime(15) is first term %e A178654 113 = emirp(10), 311 = emirp(16), 113311 / 11 = 10301 = palprime(21) is 2nd term %e A178654 14303 = emirp(414), 30341 = emirp(639), 1430330341 / 11 = 130030031 = palprime(1229), 26th term %Y A178654 Cf. A002385, A006567, A155214 %K A178654 base,nonn %O A178654 1,1 %A A178654 Ulrich Krug (leuchtfeuer37(AT)gmx.de), Jun 01 2010