A014302 a(n) = prime(n)*(prime(n-1)-1)/2.

5, 14, 33, 65, 102, 152, 207, 319, 434, 555, 738, 860, 987, 1219, 1534, 1769, 2010, 2343, 2555, 2844, 3237, 3649, 4268, 4848, 5150, 5457, 5777, 6102, 7112, 8253, 8905, 9452, 10281, 11174, 11775, 12714, 13527, 14359, 15394, 16109, 17190, 18335, 18912, 19502

Offset

3,1

Links

Robert Israel, Table of n, a(n) for n = 3..10000

Formula

a(n) = A000040(n)*A005097(n-2), if n >= 3. - Omar E. Pol, Sep 14 2013

Maple

seq(ithprime(i)*(ithprime(i-1)-1)/2, i=3..50); # Robert Israel, Jan 02 2016

Mathematica

Rest[(Last[#](First[#]-1))/2&/@Partition[Prime[Range[50]], 2, 1]] (* Harvey P. Dale, Sep 15 2011 *)

Prog

(Magma) [NthPrime(n)*(NthPrime(n-1)-1)/2: n in [3..50]]; // Vincenzo Librandi, Jan 03 2016
(PARI) a(n) = prime(n)*(prime(n-1)-1)/2; \\ Michel Marcus, Jan 03 2016
(Sage) [nth_prime(n)*(nth_prime(n-1)-1)/2 for n in (3..50)] # G. C. Greubel, Jun 12 2019

Crossrefs

Cf. A000040, A005097, A014303.

Sequence in context: A306192 A271993 A274324 * A038090 A094002 A188589

Adjacent sequences: A014299 A014300 A014301 * A014303 A014304 A014305

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved