A156027 Greater of twin primes pairs of the form k^1 + k^2 + k^3 + k^4 - 1.

5, 31, 22621, 837931, 3835261, 6377551, 16007041, 30397351, 147753211, 745720141, 987082981, 2439903211, 3276517921, 4178766091, 11468884081, 58714318141, 72695416561, 418374010741, 788251653691, 829180295191, 1029317536801, 3255573820801, 3343706188681

Offset

1,1

Comments

The corresponding values of k: 1, 2, 12, 30, 44, 50, 63, 74, 110, 165, 177, 222, 239, 254, 327, 492, 519, 804, 942, 954,...

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

2 + 2^2 + 2^3 + 2^4 - 1 = 29 and 2 + 2^2 + 2^3 + 2^4 + 1 = 31.

Mathematica

lst={}; Do[p=(n^1+n^2+n^3+n^4); If[PrimeQ[p1=p-1]&&PrimeQ[p2=p+1], AppendTo[lst, p2]], {n, 8!}]; lst

Prog

(Magma) [p+2:k in [1..1500] | IsPrime(p) and IsPrime(p+2) where p is k^1+k^2+k^3+k^4-1]; // Marius A. Burtea, Dec 21 2019

Crossrefs

Cf. A125964, A156018, A156021, A156026.

Sequence in context: A244622 A278574 A062631 * A100840 A265159 A247549

Adjacent sequences: A156024 A156025 A156026 * A156028 A156029 A156030

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Feb 01 2009

Extensions

More terms from Amiram Eldar, Dec 21 2019

Status

approved