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

1,1

Links

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

Formula

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

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

Example

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

Mathematica

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

Prog

(PARI) vector(70, n, prime(2*n) + prime(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
(Sage) [nth_prime(2*n) + nth_prime(n+1) for n in (1..70)] # G. C. Greubel, May 18 2019
(GAP) List([1..70], n-> Primes[2*n] + Primes[n+1]) # G. C. Greubel, May 18 2019

Crossrefs

Cf. A000040, A116366.

Sequence in context: A083209 A339858 A080714 * A343065 A290467 A007622

Adjacent sequences: A116365 A116366 A116367 * A116369 A116370 A116371

Keyword

nonn

Author

Reinhard Zumkeller, Feb 06 2006

Status

approved