login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A174223
Add to 2n+1 the next three primes > 2n+1.
3
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
0,1
COMMENTS
Bisection of A174221.
LINKS
MATHEMATICA
Array[Total@ Prepend[NextPrime[#, {1, 2, 3}], #] &[2 # + 1] &, 74, 0] (* Michael De Vlieger, Oct 25 2017 *)
PROG
(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
CROSSREFS
Sequence in context: A260903 A316315 A251268 * A247466 A329809 A190684
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 26 2010
STATUS
approved