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 A092120 a(n) is the first term in a sequence of primes such that a(n)+4m^2 is also prime for m = 1 to n, but composite for m = n+1. 0
 19, 3, 277, 43, 53593, 7, 67, 37, 1483087, 1867783, 9671300983, 376040154163, 13491637509487, 604490757900187, 409333 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Similar to A092474 except that a(n)+4m^2 is composite for m = n+1. a(19)=163. All other terms after a(15) are above 10^17 (if they exist). [From Jens Kruse Andersen, Oct 24 2008] LINKS Carlos Rivera, Puzzle 464. p+4*x^2. [From Jens Kruse Andersen, Oct 24 2008] EXAMPLE a(4) = 43: 43+4*1^2 = 47, which is prime. 43+4*2^2 = 59, which is prime. 43+4*3^2 = 79, which is prime. 43+4*4^2 = 107, which is prime. 43+4*5^2 = 143 = 11*13, which is composite. CROSSREFS Sequence in context: A040352 A040353 A128160 * A002206 A040349 A040350 Adjacent sequences:  A092117 A092118 A092119 * A092121 A092122 A092123 KEYWORD nonn AUTHOR Ray G. Opao, Mar 29 2004 EXTENSIONS Correction and a(11) - a(15) from Jens Kruse Andersen, Oct 24 2008 STATUS approved

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