A138419 a(n) = (prime(n)^4 - prime(n)^2)/3.

4, 24, 200, 784, 4840, 9464, 27744, 43320, 93104, 235480, 307520, 624264, 941360, 1138984, 1625824, 2629224, 4037960, 4614040, 6715544, 8468880, 9464304, 12981280, 15817144, 20911440, 29506624, 34683400, 37513424, 43689384

Offset: 1

Author

Artur Jasinski, Mar 19 2008

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200

Programs

Magma

[(NthPrime((n))^4 - NthPrime((n))^2)/3: n in [1..30] ]; // Vincenzo Librandi, Jun 17 2011

Mathematica

a = {}; Do[p = Prime[n]; AppendTo[a, (p^4 - p^2)/3], {n, 1, 50}]; a
(#^4-#^2)/3&/@Prime[Range[30]] (* Harvey P. Dale, Jun 30 2017 *)

PARI

forprime(p=2,1e3,print1((p^4-p^2)/3", ")) \\ Charles R Greathouse IV, Jul 15 2011

Formula

a(n) = A138402(n)/3. - R. J. Mathar, Oct 15 2017