A241265 Numbers n such that n^4+(n+1)^4 is not prime.

5, 7, 10, 11, 15, 17, 18, 19, 20, 21, 22, 23, 24, 28, 29, 30, 32, 35, 39, 41, 42, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 69, 70, 71, 73, 75, 76, 77, 79, 80, 81, 83, 84, 85, 86, 90, 91, 92, 93, 94, 95, 96, 99, 100, 101

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Formula

7 is in this sequence because 7^4+8^4 = 6497 = 73*89.

Mathematica

Select[Range[200], ! PrimeQ[#^4 + (# + 1)^4] &]
Position[Total/@Partition[Range[120]^4, 2, 1], _?CompositeQ]//Flatten (* Harvey P. Dale, Mar 31 2024 *)

Prog

(Magma) [n: n in [1..200] | not IsPrime(n^4+(n+1)^4)];

Crossrefs

Complement of A155211.

Sequence in context: A028759 A278579 A088707 * A189290 A129415 A075275

Adjacent sequences: A241262 A241263 A241264 * A241266 A241267 A241268

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 20 2014

Status

approved