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 A101824 #24 Jan 17 2019 13:44:06 %S A101824 0,1,4,7,23,28,83,109,128,175,592,1136,2674,4991,26903,31571,55076, %T A101824 81020,122273 %N A101824 Indices of primes in sequence defined by A(0) = 37, A(n) = 10*A(n-1) - 63 for n > 0. %C A101824 Numbers n such that 30*10^n + 7 is prime. %C A101824 Numbers n such that digit 3 followed by n >= 0 occurrences of digit 0 followed by digit 7 is prime. %C A101824 Certified primality of term 1136 using Primo. - _Ryan Propper_, Jun 18 2005 %C A101824 a(19) > 10^5. - _Robert Price_, Jan 26 2015 %C A101824 a(20) > 2*10^5. - _Robert Price_, Jul 04 2015 %D A101824 Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467. %H A101824 Makoto Kamada, <a href="https://stdkmd.net/nrr/3/30007.htm#prime">Prime numbers of the form 300...007</a>. %F A101824 a(n) = A100501(n) - 1. %e A101824 307 is prime, hence 1 is a term. %o A101824 (PARI) a=37;for(n=0,1500,if(isprime(a),print1(n,","));a=10*a-63) %o A101824 (PARI) for(n=0,1500,if(isprime(30*10^n+7),print1(n,","))) %Y A101824 Cf. A000533, A002275, A100501. %K A101824 nonn,hard,more %O A101824 1,3 %A A101824 _Klaus Brockhaus_ and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 20 2004 %E A101824 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008 %E A101824 a(16)-a(18) derived from A100501 by _Robert Price_, Jan 26 2015 %E A101824 a(19) from _Robert Price_, Jul 04 2015