A155929 Integers a(n) such that cube(n)-square(n)-1 and cube(n)+square(n)+1 are primes.

2, 3, 9, 12, 30, 57, 66, 87, 111, 120, 195, 243, 246, 279, 378, 381, 432, 450, 471, 480, 597, 651, 759, 810, 933, 987, 1053, 1356, 1362, 1404, 1407, 1410, 1548, 1563, 1638, 1752, 1758, 1998, 2016, 2115, 2157, 2259, 2280, 2385, 2499, 2607, 2775, 2817, 2826

Offset

1,1

Comments

2^3-2^2-1=3;2^3+2^2+1=13, 3^3-3^2-1=17;3^3+3^2+1=37, ...

Links

Table of n, a(n) for n=1..49.

Mathematica

lst={}; Do[c=n^3; s=n^2; p1=c-s-1; p2=c+s+1; If[PrimeQ[p1]&&PrimeQ[p2], AppendTo[lst, n]], {n, 7!}]; lst

Crossrefs

Sequence in context: A330242 A239859 A047162 * A175206 A032486 A123859

Adjacent sequences: A155926 A155927 A155928 * A155930 A155931 A155932

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jan 30 2009

Status

approved