A116368 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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 *)