A156026 Lesser of twin primes of the form k^1 + k^2 + k^3 + k^4 - 1.

3, 29, 22619, 837929, 3835259, 6377549, 16007039, 30397349, 147753209, 745720139, 987082979, 2439903209, 3276517919, 4178766089, 11468884079, 58714318139, 72695416559, 418374010739, 788251653689, 829180295189

Offset

1,1

Comments

The corresponding values of k are 1, 2, 12, 30, 44, ... (A156021).

Links

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

Example

29 is a term since 2 + 2^2 + 2^3 + 2^4 - 1 = 29 and 2 + 2^2 + 2^3 + 2^4 + 1 = 31 are twin primes.

Mathematica

lst={}; Do[p=(n^1+n^2+n^3+n^4); If[PrimeQ[p1=p-1]&&PrimeQ[p2=p+1], AppendTo[lst, p1]], {n, 8!}]; lst
Select[Table[n+n^2+n^3+n^4-1, {n, 1000}], AllTrue[{#, #+2}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 17 2019 *)

Crossrefs

Cf. A001359, A125964, A156018, A156021.

Sequence in context: A229051 A006526 A139517 * A171883 A112981 A178336

Adjacent sequences: A156023 A156024 A156025 * A156027 A156028 A156029

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Feb 01 2009

Status

approved