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 A100999 #16 Jan 17 2019 13:44:06 %S A100999 0,16,22,72,130,472,684,700,1908,3028,3472,4192,9930 %N A100999 Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 53 for n > 0. %C A100999 Numbers n such that (820*10^n + 53)/9 is prime. %C A100999 Numbers n such that digit 9 followed by n >= 0 occurrences of digit 1 followed by digit 7 is prime. %C A100999 Numbers corresponding to terms <= 700 are certified primes. %C A100999 a(14) > 10^5. - _Robert Price_, Oct 25 2015 %D A100999 Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467. %H A100999 Makoto Kamada, <a href="https://stdkmd.net/nrr/9/91117.htm#prime">Prime numbers of the form 911...117</a>. %H A100999 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>. %F A100999 a(n) = A100473(n) - 1. %e A100999 911111111111111117 is prime, hence 16 is a term. %t A100999 Select[Range[0, 100000], PrimeQ[(820*10^# + 53)/9] &] (* _Robert Price_, Oct 25 2015 *) %o A100999 (PARI) a=97;for(n=0,1000,if(isprime(a),print1(n,","));a=10*a-53) %o A100999 (PARI) for(n=0,1000,if(isprime((820*10^n+53)/9),print1(n,","))) %Y A100999 Cf. A000533, A002275, A100473. %K A100999 nonn,hard,more %O A100999 1,2 %A A100999 _Klaus Brockhaus_ and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Nov 27 2004 %E A100999 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008