A174223 Add to 2n+1 the next three primes > 2n+1.

11, 26, 36, 48, 50, 60, 72, 74, 88, 102, 104, 120, 122, 124, 138, 152, 154, 156, 168, 170, 184, 202, 204, 220, 222, 224, 240, 242, 244, 258, 272, 274, 276, 290, 292, 306, 324, 326, 328, 348, 350, 370, 372, 374, 390, 392, 394, 396, 408, 410, 420, 432, 434, 456, 480, 482, 508, 510, 512, 514, 516, 518, 520, 534, 536, 556, 558, 560, 576, 596, 598, 600, 602, 604

Offset: 0

Author

N. J. A. Sloane, Nov 26 2010

Keywords

• nonn

Comments

Bisection of A174221.

Links

• Michael De Vlieger, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A174221, A193230.

Programs

Mathematica

Array[Total@ Prepend[NextPrime[#, {1, 2, 3}], #] &[2 # + 1] &, 74, 0] (* Michael De Vlieger, Oct 25 2017 *)

PARI

A174223(n)=sum(c=1, 3, n=nextprime(n+1),n=2*n+1) \\ M. F. Hasler, Oct 25 2017

Python

from sympy import nextprime
def a(n):
    base = 2*n + 1
    p1 = nextprime(base)
    p2 = nextprime(p1)
    p3 = nextprime(p2)
    return base + p1 + p2 + p3
print([a(n) for n in range(74)]) # Michael S. Branicky, Nov 26 2021