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 A090819 #29 Oct 25 2024 06:50:24 %S A090819 2,19,31,37,41,53,59,61,67,71,73,79,89,97,101,103,107,109,113,127,139, %T A090819 149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,233, %U A090819 239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349 %N A090819 Primes p such that the p-th Fibonacci number is nonprime. %C A090819 Is it true that a(n) ~ n log n? - _Charles R Greathouse IV_, Aug 15 2015 %F A090819 a(n) = prime(A134787(n)). - _Amiram Eldar_, Oct 25 2024 %e A090819 Fibonacci(37) = 24157817 = 73*149*2221. [corrected by _Bobby Jacobs_, Sep 25 2017] %t A090819 Select[Prime[Range[62]], ! PrimeQ[Fibonacci[#]] &] (* _Jayanta Basu_, Jul 10 2013 *) %o A090819 (PARI) f(n) = forprime(x=2,n,p=fibonacci(x);if(!isprime(p),print1(x","))) %Y A090819 Cf. A000045, A001605, A134787. %Y A090819 Essentially the same as A038672. %K A090819 easy,nonn %O A090819 1,1 %A A090819 _Cino Hilliard_, Feb 11 2004 %E A090819 Definition corrected by _Don Reble_, Sep 04 2008