A127919 1/3 of product of three numbers: the n-th prime, the previous number and the following number.

2, 8, 40, 112, 440, 728, 1632, 2280, 4048, 8120, 9920, 16872, 22960, 26488, 34592, 49608, 68440, 75640, 100232, 119280, 129648, 164320, 190568, 234960, 304192, 343400, 364208, 408312, 431640, 480928, 682752, 749320, 857072, 895160, 1102600

Offset

1,1

Comments

Number of irreducible monic cubic polynomials over GF(prime(n)). - Robert Israel, Jan 06 2015

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

a(n) = (prime(n)^3 - prime(n))/3. - Wesley Ivan Hurt, Oct 15 2023

Maple

seq((ithprime(n)^3 - ithprime(n))/3, n=1..100); # Robert Israel, Jan 06 2015

Mathematica

Table[(Prime[n] + 1) Prime[n] (Prime[n] - 1)/3, {n, 100}]

Prog

(PARI) forprime(p=2, 1e3, print1(2*binomial(p+1, 3)", ")) \\ Charles R Greathouse IV, Jun 16 2011
(Magma) [(p^3 - p) div 3: p in PrimesUpTo(150)]; // Vincenzo Librandi, Jan 08 2015

Crossrefs

Cf. A036689, A034953, A127917, A127918, A127920.

Sequence in context: A154132 A152458 A087971 * A366478 A074092 A003445

Adjacent sequences: A127916 A127917 A127918 * A127920 A127921 A127922

Keyword

nonn,easy

Author

Artur Jasinski, Feb 06 2007

Status

approved