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 A090195 #11 Dec 31 2019 16:58:40 %S A090195 2,41,163,181,211,431,463,613,653,853,1163,1381,1483,1613,1801,1861, %T A090195 1873,2011,2063,2141,2221,2243,2411,2633,2851,3041,3181,3583,3623, %U A090195 4211,4241,4363,4421,4463,4483,4603,5563,5581,5821,5851,6113,6143,6203,6553 %N A090195 Primes which when multiplied by their largest digit and 1 is subtracted form another prime. %H A090195 Harvey P. Dale, <a href="/A090195/b090195.txt">Table of n, a(n) for n = 1..1000</a> %F A090195 In the prime sequence, select largest digit in each prime, multiply by the prime containing that digit, then subtract 1. If the result is another prime, add to sequence. %e A090195 a(2)=41. Largest digit is 4. Multiply 41*4=164. 164-1=163, prime. %t A090195 Select[Prime[Range[1000]],PrimeQ[# Max[IntegerDigits[#]]-1]&] (* _Harvey P. Dale_, Dec 31 2019 *) %o A090195 (PARI) isok(p) = isprime(p) && isprime(p*vecmax(digits(p))-1); \\ _Michel Marcus_, Jun 08 2014 %Y A090195 Cf. A060418. %K A090195 easy,nonn,base %O A090195 1,1 %A A090195 _Enoch Haga_, Jan 22 2004