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A130676

Numbers n for which either 16*n^2-6*n+1 or 16*n^2-10*n-1 or both is/are prime.

1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 15, 16, 17, 18, 20, 22, 23, 25, 27, 28, 30, 32, 33, 35, 36, 37, 38, 39, 42, 43, 44, 46, 48, 50, 52, 57, 59, 60, 63, 65, 67, 68, 70, 71, 72, 73, 76, 80, 81, 85, 87, 88, 90, 92, 93, 94, 95, 98, 101, 102, 103, 104, 105, 108, 110, 112, 113, 115, 118, 120, 123, 125, 128, 129, 132, 134

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OFFSET

1,2

COMMENTS

Consider the two forms (4*n-2)*4*n +- (2*n+1), where "+-" generates two different terms 16*n^2-6*n+1 and 16*n^2-10*n-1 for n=1,2,3,...

If at least one of the two numbers is prime, n is inserted into the sequence.

LINKS

Table of n, a(n) for n=1..76.

EXAMPLE

For n=20, 16*20^2 - 10*20 - 1= (4*20-2)*4*20-(2*20+1) = 6199 is prime, which adds 20 to the sequence.

For n=15, 16*15^2 - 6*15 +1= (4*15-2)*4*15 +(2*15+1) = 3511 is prime, which adds 15 to the sequence.

CROSSREFS