A135277 a(n) = prime(2n-1) + prime(2n) + prime(2n+1).

10, 23, 41, 59, 83, 109, 131, 159, 187, 211, 235, 269, 301, 319, 349, 395, 425, 457, 487, 519, 551, 581, 607, 661, 689, 713, 749, 789, 817, 841, 883, 931, 961, 1015, 1049, 1079, 1119, 1151, 1187, 1229, 1271, 1303, 1331, 1367, 1391, 1433, 1477, 1511, 1553, 1611

Offset

1,1

Comments

Original name was: Sum of staircase primes according to the rule: bottom + top + next top.

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Formula

We list the primes in staircase fashion as in A135274. The right diagonal, RD(n), is the set of top primes and the left diagonal, LD(n), is the set of bottom primes. Then a(n) = LD(n+1) + RD(n) + RD(n+2).

a(n) = A034961(2*n-1). - R. J. Mathar, Sep 10 2016

Mathematica

Table[Prime[n + 1] + Prime[n] + Prime[n + 2], {n, 1, 50}][[;; ;; 2]] (* G. C. Greubel, Oct 08 2016 *)

Prog

(PARI) g(n) = forstep(x=1, n, 2, y=prime(x+1) + prime(x) + prime(x+2); print1(y", "))
(PARI) a(n) = prime(2*n-1) + prime(2*n) + prime(2*n+1) \\ Charles R Greathouse IV, Oct 08 2016
(Python)
from sympy import prime
def a(n): return prime(2*n-1) + prime(2*n) + prime(2*n+1)
print([a(n) for n in range(1, 51)]) # Michael S. Branicky, Oct 23 2021

Crossrefs

Cf. A034961, A135274.

Sequence in context: A275238 A140674 A072245 * A156202 A266080 A316093

Adjacent sequences: A135274 A135275 A135276 * A135278 A135279 A135280

Keyword

nonn,easy

Author

Cino Hilliard, Dec 02 2007

Extensions

New name from Charles R Greathouse IV, Oct 08 2016

Status

approved