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 A158648 #10 Mar 21 2018 15:32:42 %S A158648 0,1,3,4,5,6,7,8,10,11,15,18,19,20,21,22,26,27,28,29,31,32,36,39,40, %T A158648 42,43,45,47,49,53,54,55,56,59,61,62,63,66,67,69,73,74,75,76,78,80,81, %U A158648 82,88,89,92,94,96,97,98,104,105,108,111,113,115,117,118,120,122,125,126 %N A158648 Numbers n such that 30*n + 17 is prime. %C A158648 Encoded primes with LSD 7 and (SOD-1)/3 non-integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime. %F A158648 a(n) = (A039949(n) - 17)/30 = Floor[A039949(n)/30]. - Chandler %e A158648 Example: 3557, with LSD 7 and (SOD-1)/3 = 6.333 (non-integer); Then 7557/30 = 118.566, or 118 which is in the sequence, and thus 3557 is prime. %t A158648 Select[Range[0,200],PrimeQ[30#+17]&] (* _Harvey P. Dale_, Mar 21 2018 *) %o A158648 (PARI) is(n)=isprime(30*n+17) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A158648 Cf. A111175, A158573, A158614, A158746, A158791, A158806, A158850. %K A158648 nonn %O A158648 1,3 %A A158648 _Ki Punches_, Mar 23 2009 %E A158648 Edited by _Ray Chandler_, Apr 07 2009