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A106563 Numbers n such that n^2 is not the sum of two primes. 2
1, 11, 17, 23, 25, 31, 39, 41, 45, 51, 53, 57, 59, 65, 67, 73, 79, 81, 83, 85, 87, 91, 95, 97, 99, 101, 105, 109, 111, 113, 115, 123, 125, 129, 133, 137, 141, 143, 147, 149, 151, 153, 157, 159, 163, 165, 167, 171, 175, 179, 181, 185, 187, 189, 193, 195, 197, 199, 201 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..59.

FORMULA

a(n) = SQRT(A106562(n)).

EXAMPLE

a(3)=17 because the third square which is not the sum of two primes (289=17^2) is the 17th one in the succession of the perfect squares (thus: index 17).

CROSSREFS

Cf. A106544-A106548, A106562-A106564, A106571, A106573-A106575, A106577.

Sequence in context: A184551 A190039 A066074 * A106574 A171125 A156781

Adjacent sequences:  A106560 A106561 A106562 * A106564 A106565 A106566

KEYWORD

nonn

AUTHOR

Alexandre Wajnberg, May 09 2005

EXTENSIONS

Extended by Ray Chandler, May 12 2005

STATUS

approved

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Last modified October 15 13:01 EDT 2018. Contains 316236 sequences. (Running on oeis4.)