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 A106571 Indices n of perfect squares n^2 which are not the difference of two primes. 16
 5, 7, 11, 13, 17, 19, 23, 25, 27, 29, 31, 35, 37, 41, 43, 47, 49, 51, 53, 55, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 83, 85, 87, 89, 91, 93, 95, 97, 101, 103, 107, 109, 113, 115, 119, 121, 125, 127, 129, 131, 133, 135, 137, 139, 141, 143, 145, 149, 151, 153, 155 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also, n such that 1+n^2 is a nontotient (A005277). - T. D. Noe, Sep 13 2007 LINKS T. D. Noe, Table of n, a(n) for n=1..1000 FORMULA a(n) = SQRT(A106564(n)). EXAMPLE a(3)=11 because the third square which is not the difference of two primes (121=11^2) is the 11-th one in the succession of the perfect squares (thus index 11). CROSSREFS Cf. A106544-A106548, A106562-A106564, A106573-A106575, A106577. Cf. A067201 (n such that n^2+2 is prime) Sequence in context: A111906 A101550 A136801 * A067291 A007310 A069040 Adjacent sequences:  A106568 A106569 A106570 * A106572 A106573 A106574 KEYWORD easy,nonn AUTHOR Alexandre Wajnberg, May 09 2005 EXTENSIONS Extended by Ray Chandler, May 12 2005 STATUS approved

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