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 A090874 a(n) is the smallest number m such that m^2^k + (m+1)^2^k is prime for k=0..n. 3
 1, 1, 1, 1, 1, 1806390369, 218327374070, 3697211121741701604 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 COMMENTS The first five terms of this sequence correspond to Fermat primes. LINKS Table of n, a(n) for n=0..7. EXAMPLE a(5)=1806390369 because this is the smallest number m such that m^2^k + (m+1)^2^k is prime for k=0,1,2,3,4 and 5. CROSSREFS Cf. A090872, A090873, A019434, A000215. Sequence in context: A129616 A105006 A318788 * A071371 A052094 A256123 Adjacent sequences: A090871 A090872 A090873 * A090875 A090876 A090877 KEYWORD nonn,hard,more AUTHOR Farideh Firoozbakht, Feb 06 2004 EXTENSIONS a(6) found by Kellen Shenton added by Jeppe Stig Nielsen, Mar 28 2022 a(7) from Kellen Shenton, Aug 27 2022 STATUS approved

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Last modified December 10 19:02 EST 2023. Contains 367717 sequences. (Running on oeis4.)