A138417 a(n) = (prime(n)^4 - prime(n))/2.

7, 39, 310, 1197, 7315, 14274, 41752, 65151, 139909, 353626, 461745, 937062, 1412860, 1709379, 2439817, 3945214, 6058651, 6922890, 10075527, 12705805, 14199084, 19475001, 23729119, 31371076, 44264592, 52030150, 56275389

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: n in [1..30] ]; // Vincenzo Librandi, Jun 17 2011

Mathematica

a = {}; Do[p = Prime[n]; AppendTo[a, (p^4 - p)/2], {n, 1, 50}]; a
(#^4-#)/2&/@Prime[Range[50]]  (* Harvey P. Dale, Mar 21 2011 *)

PARI

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

Formula

a(n) = A138401(n)/2. - R. J. Mathar, Oct 15 2017