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 A249667 Numbers n such that the sum of n and the largest primen is also prime. 4
 6, 24, 30, 36, 50, 54, 78, 84, 114, 132, 144, 156, 174, 210, 220, 252, 294, 300, 306, 330, 360, 378, 474, 492, 510, 512, 528, 546, 560, 594, 610, 650, 660, 690, 714, 720, 762, 780, 800, 804, 810, 816, 870, 912, 996, 1002, 1068, 1074, 1104, 1120, 1170, 1176, 1190, 1210, 1236, 1262 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is the intersection of A249624 and A249666. LINKS Chai Wah Wu, Table of n, a(n) for n = 1..3410 EXAMPLE 114 is in the sequence because the least prime>114 is 127 and 114+127=241 is prime; the largest prime<114 is 113 and 114+113=227 is prime. Also, 114 is in A249624 and A249666. MATHEMATICA Select[Range[1500], AllTrue[#+{NextPrime[#], NextPrime[#, -1]}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 09 2016 *) PROG (PARI) {for(i=3, 2*10^3, k=i+nextprime(i+1); q=i+precprime(i-1); if(isprime(k)&&isprime(q), print1(i, ", ")))} (Python) from gmpy2 import is_prime, next_prime A249667_list, p = [], 2 for _ in range(10**4): ....q = next_prime(p) ....n1 = 2*p+1 ....n2 = p+q+1 ....while n1 < p+q: ........if is_prime(n1) and is_prime(n2): ............A249667_list.append(n1-p) ........n1 += 2 ........n2 += 2 ....p = q # Chai Wah Wu, Dec 06 2014 CROSSREFS Cf. A249624, A249666, A249676. Sequence in context: A294900 A064510 A228383 * A114274 A292985 A234648 Adjacent sequences:  A249664 A249665 A249666 * A249668 A249669 A249670 KEYWORD nonn AUTHOR Antonio Roldán, Dec 03 2014 STATUS approved

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Last modified September 21 19:29 EDT 2018. Contains 315260 sequences. (Running on oeis4.)