cp's OEIS Frontend

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.

A273010 Numbers n such that (9^n - 7^n)/2 is prime.

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%I A273010 #10 Jul 29 2023 22:37:19
%S A273010 3,5,7,4703,30113,835391
%N A273010 Numbers n such that (9^n - 7^n)/2 is prime.
%C A273010 All terms are prime.
%C A273010 The corresponding primes: 193, 21121, 1979713, ...
%H A273010 Jon Grantham and Andrew Granville, <a href="https://arxiv.org/abs/2307.07894">Fibonacci primes, primes of the form 2^n-k and beyond</a>, arXiv:2307.07894 [math.NT], 2023.
%t A273010 Select[Range[1, 10000], PrimeQ[(9^# - 7^#)/2] &]
%o A273010 (PARI) for(n=1,10000, if(isprime((9^n - 7^n)/2), print1(n,", ")))
%Y A273010 Cf. A081202, A173718, A128346, A059803.
%K A273010 nonn,more,hard
%O A273010 1,1
%A A273010 _Tim Johannes Ohrtmann_, May 13 2016
%E A273010 a(6) from _Jon Grantham_, Jul 29 2023