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A293206
a(n) = prime(n) + prime(n+1) * prime(n+2).
1
17, 38, 82, 150, 232, 336, 454, 686, 922, 1176, 1548, 1800, 2062, 2534, 3174, 3652, 4146, 4818, 5250, 5838, 6630, 7466, 8716, 9886, 10500, 11122, 11766, 12424, 14460, 16750, 18074, 19174, 20848, 22638, 23856, 25742, 27378, 29054, 31134, 32572, 34750, 37044, 38212, 39396
OFFSET
1,1
COMMENTS
Only the first term of the sequence is prime. The remaining terms are all composite as they are of the form 2*k with k > 1.
EXAMPLE
As prime(1) + prime(1 + 1) * prime(1 + 2) = 2 + 3*5 = 17, a(1) = 17.
MATHEMATICA
#[[1]]+#[[2]]#[[3]]&/@Partition[Prime[Range[50]], 3, 1] (* Harvey P. Dale, Nov 02 2021 *)
PROG
(PARI) first(n) = my(v = vector(n), p = 1, q = 2, r = 3); for(i=1, n, p = q; q = r; r = nextprime(r + 1); v[i] = p + q*r); v \\ David A. Corneth, Oct 02 2017
CROSSREFS
Sequence in context: A121710 A051779 A139579 * A125248 A259489 A226127
KEYWORD
nonn
AUTHOR
STATUS
approved