A116368 Central terms of the triangle in A116366.

6, 12, 20, 30, 42, 54, 62, 76, 90, 102, 116, 130, 144, 154, 166, 190, 200, 218, 234, 246, 260, 276, 288, 320, 330, 342, 358, 372, 384, 408, 424, 448, 456, 486, 500, 516, 536, 550, 570, 588, 602, 624, 636, 654, 662, 690, 714, 730, 750, 774, 796, 810, 828, 850, 864, 882, 890, 918, 928

Offset: 1

Author

Reinhard Zumkeller, Feb 06 2006

Keywords

• nonn

Examples

			For n=4, prime(2n) = prime(8) = 19, and prime(n+1) = prime(5) = 11, so a(4) = 19 + 11 = 30. - _Michael B. Porter_, Aug 15 2016
		

Links

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

Crossrefs

Cf. A000040, A116366.

Programs

GAP

List([1..70], n-> Primes[2*n] + Primes[n+1]); # G. C. Greubel, May 18 2019

Magma

[NthPrime(2*n) + NthPrime(n+1): n in [1..70]]; // G. C. Greubel, May 18 2019

Mathematica

Table[Prime[2n] + Prime[n+1], {n, 1, 70}](* Terry D. Grant, Aug 15 2016 *)

PARI

vector(70, n, prime(2*n) + prime(n+1)) \\ G. C. Greubel, May 18 2019

Sage

[nth_prime(2*n) + nth_prime(n+1) for n in (1..70)] # G. C. Greubel, May 18 2019

Formula

a(n) = A000040(2n) + A000040(n+1).

a(n) = A116366(2*n-1, n).