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 A121978 Numbers n such that (2n^2)^8 + 1 is prime. 1
 1, 11, 12, 14, 20, 27, 29, 30, 40, 65, 71, 85, 87, 89, 97, 104, 115, 147, 155, 175, 181, 189, 194, 244, 263, 264, 285, 286, 291, 303, 354, 360, 370, 376, 403, 407, 417, 423, 429, 433, 448, 479, 492, 493, 520, 570, 582, 588, 596, 617, 627, 629, 644, 654, 661 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Corresponding primes of the form (2n^2)^8 + 1 are {257, 11763130845074473217, 47330370277129322497, 557556054479199010817, 167772160000000000000001, ...}. There are consecutive twin pairs {a(n),a(n+1)} = {11,12}, {29,30}, {263,264},{285,286}, {492,493}, {833,834}, ... LINKS G. C. Greubel, Table of n, a(n) for n = 1..5000 MATHEMATICA Select[Range[1000], PrimeQ[(2*#1^2)^8+1]&] Select[Range[1000], PrimeQ[256#^16+1]&] (* Harvey P. Dale, Nov 04 2020 *) PROG (PARI) is(n)=isprime((2*n^2)^8+1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A006314. Sequence in context: A246139 A034907 A045987 * A274566 A349153 A213309 Adjacent sequences:  A121975 A121976 A121977 * A121979 A121980 A121981 KEYWORD nonn,easy AUTHOR Alexander Adamchuk, Sep 10 2006 STATUS approved

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Last modified January 28 12:38 EST 2022. Contains 350656 sequences. (Running on oeis4.)