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A140538 Greatest prime factor of 2*n^4+1. 0
3, 11, 163, 19, 139, 2593, 1601, 2731, 1193, 113, 227, 619, 577, 8537, 73, 43691, 55681, 209953, 307, 9697, 388963, 52057, 1091, 337, 260417, 304651, 3011, 4937, 471521, 1620001, 691, 5419, 32491, 46889, 90947, 25643, 11057, 15619, 7499, 7793 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

a(n) = A006530(2n^4+1) = A076565(n^4). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 04 2008]

EXAMPLE

a(2)= 11 because 2*2^4+1 = 33 = 3*11, greatest prime factor is 11.

CROSSREFS

Sequence in context: A010682 A080987 A132561 * A006485 A003115 A053888

Adjacent sequences:  A140535 A140536 A140537 * A140539 A140540 A140541

KEYWORD

easy,nonn

AUTHOR

Donald S. McDonald (MCDOnewt(AT)yahoo.co.nz), Jul 06 2008

EXTENSIONS

Extended from a(16) on, R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 04 2008

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Last modified February 15 14:57 EST 2012. Contains 205823 sequences.