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 A321353 #25 Jan 10 2019 23:20:34 %S A321353 4,5,6,7,8,9,12,13,16,17,18,21,23,29,31,33,35,36,41,58,63,66,69,82,96, %T A321353 99,148,157,175,196,241,267,349,394,404,414,435,456,485,498,537,548, %U A321353 584,715,727,765,929,1007,1076,1399,1619,1652,1715,2758,3039,3131,3773,3822,5001 %N A321353 Numbers k such that 3*2^k - 25 is prime. %C A321353 Appears (at least initially) to contain more primes that the analogous sequences for 2^k-1 or 2^k-3. Compare the comment of Paul Bourdelais in A050414. %e A321353 7 is a term, because 3*2^7 - 25 = 359 is prime. %t A321353 Select[Range[100], PrimeQ[3 2^# - 25] &] %o A321353 (PARI) for(n=0, 2000, if(ispseudoprime(p=3*2^n-25), print1(n, ", "))); %Y A321353 Cf. A050414. %K A321353 nonn %O A321353 1,1 %A A321353 _Gilbert Mozzo_, Nov 07 2018