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 A301919 #22 May 07 2018 13:30:22 %S A301919 0,1,3,4,9,10,15,16,10,5,22,27,6,12,7,40,45,25,51,18,57,64,69,70,75, %T A301919 26,40,82,87,9,99,100,106,112,117,61,129,135,16,141,142,147,18,159, %U A301919 166,85,88,177,62,94,190,195,100,201,103,74,225,115,231,232,244,84 %N A301919 a(n) is the least value of k for which A301918(n) divides 3^k+3. %C A301919 This can be used to identify P+1 values to primality test potential primes P of the form 3^k+2, i.e., A051783. %F A301919 a(n) = A301917(n-1) + 1 for n > 2. %e A301919 All values of 3^k+3 are multiples of 2, so 3^0+3 = 4 is the least value of k which is a multiple of 2. %e A301919 a(10) = 5 and A301918(10) = 41 so 3^5+3 = 246 is the first multiple of 41 which can be written in the form 3^k+3. %Y A301919 Cf. A051783, A178674, A301916, A301917, A301918. %K A301919 nonn %O A301919 1,3 %A A301919 _Luke W. Richards_, Mar 28 2018