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A338701 Sums of two odd-indexed primes. 1

%I #13 Apr 29 2021 21:59:43

%S 4,7,10,13,16,19,22,25,28,33,34,36,40,42,43,46,48,49,52,54,58,61,62,

%T 64,69,70,72,75,76,78,82,84,85,88,90,94,96,98,99,100,102,104,105,106,

%U 108,111,114,118,120,124,126,128,129,130,132,134,138,139,140,142,144,146,148,150

%N Sums of two odd-indexed primes.

%t Take[Union[Total /@ Tuples[Prime[2 Range[70] - 1], 2]], 70]

%o (Python)

%o from sympy import primerange

%o def aupto(limit):

%o op = [p for p in primerange(1, limit)][::2]

%o ss = sorted(set(p1 + p2 for i, p1 in enumerate(op) for p2 in op[i:]))

%o return [s for s in ss if s <= limit]

%o print(aupto(150)) # _Michael S. Branicky_, Apr 24 2021

%o (PARI) my(N=18); select(x->(x<prime(1)+prime(2*N+1)), setbinop((x,y)->(x+y), vector(N, n, prime(2*n-1)))) \\ _Michel Marcus_, Apr 24 2021

%Y Cf. A031368 (odd-indexed primes), A338703 (sums of two even-indexed primes).

%K nonn

%O 1,1

%A _Wesley Ivan Hurt_, Apr 24 2021

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Last modified May 14 17:50 EDT 2024. Contains 372533 sequences. (Running on oeis4.)