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 A202105 #15 Aug 26 2025 20:14:53 %S A202105 0,2,3,7,9,11,12,13,14,16,18,19,21,23,24,25,26,27,31,37,38,40,41,42, %T A202105 44,45,47,48,52,53,54,55,60,62,67,68,70,74,75,76,80,81,84,87,88,89,91, %U A202105 98,100,101,104,114,118,119,123,126,130,131,132,137,139,142 %N A202105 Numbers k such that 90*k + 43 is prime. %C A202105 This sequence was generated by adding 12 Fibonacci-like sequences [See: PROG]. Looking at the format 90k+43 modulo 9 and modulo 10 we see that all entries of A142334 have digital root 7 and last digit 3. (Reverting the process is an application of the Chinese remainder theorem.) The 12 Fibonacci-like sequences are generated (via the p and q values given in the PERL program) from the base p,q pairs 43*91, 19*7, 37*79, 73*61, 11*53, 29*17, 47*89, 83*71, 13*31, 49*67, 23*41, 59*77. %t A202105 Select[Range[0, 200], PrimeQ[90 # + 43] &] %o A202105 (PARI) is(n)=isprime(90*n+43) \\ _Charles R Greathouse IV_, Feb 17 2017 %Y A202105 Cf. A181732, A198382, A195993, A196000, A196007, A201739, A201734, A201804, A201816, A201817, A201818, A201820, A201822, A202101, A202104. %K A202105 easy,nonn,changed %O A202105 1,2 %A A202105 _J. W. Helkenberg_, Dec 11 2011