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 A060377 Pepin's test numbers. 1
 3, 9, 6561, 11790184577738583171520872861412518665678211592275841109096961 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Next two terms have 15635 and 1024610093 digits respectively. [Corrected by Michael S. Branicky and Sean A. Irvine, Nov 12 2022] LINKS C. K. Caldwell, Pepin's Test FORMULA a(n) = 3^((F(n)-1)/2) where F(n) is a Fermat number (A000215). EXAMPLE a(1) = 3^((F(1)-1)/2) = 3^((5-1)/2) = 3^2 = 9. PROG (Python) def a(n): return 3**(2**(2**n-1)) print([a(n) for n in range(4)]) # Michael S. Branicky, Nov 12 2022 CROSSREFS Sequence in context: A060712 A122463 A072005 * A255503 A027896 A116620 Adjacent sequences: A060374 A060375 A060376 * A060378 A060379 A060380 KEYWORD nonn AUTHOR Jason Earls, Apr 02 2001 EXTENSIONS Corrected offset, formula and example Harry J. Smith, Jul 04 2009 STATUS approved

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Last modified February 5 15:20 EST 2023. Contains 360086 sequences. (Running on oeis4.)