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 A275382 Number of odd prime factors (with multiplicity) of generalized Fermat number 11^(2^n) + 1. 2
 1, 1, 1, 2, 2, 3, 2, 5, 6 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS FORMULA a(n) = A001222(A199592(n)) - 1 for n > 0. - Felix Fröhlich, Jul 25 2016 EXAMPLE b(n) = (11^(2^n) + 1)/2. Complete Factorizations b(0) = 2*3 b(1) = 61 b(2) = 7321 b(3) = 17*6304673 b(4) = 51329*447600088289 b(5) = 193*257*21283620033217629539178799361 b(6) = 316955440822738177*P49 b(7) = 15361*111489577217*574341646346402207998363393*        4018529583345312964042058778793458689*P55 b(8) = 15190529*4696846849*19618834249745000485889*        4393553986026616439660661873903822389581313*        290103547098489711747952055517085778590240759297*P138 PROG (PARI) a001222(n) = bigomega(n) a199592(n) = 11^(2^n)+1 a(n) = if(n==0, 1, a001222(a199592(n))-1) \\ Felix Fröhlich, Jul 25 2016 CROSSREFS Cf. A199592, A273949. Sequence in context: A050323 A318286 A214646 * A199583 A157922 A015995 Adjacent sequences:  A275379 A275380 A275381 * A275383 A275384 A275385 KEYWORD nonn,hard,more AUTHOR Arkadiusz Wesolowski, Jul 25 2016 EXTENSIONS a(8) was found in 2006 by Bruce Dodson STATUS approved

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Last modified January 18 13:47 EST 2020. Contains 331009 sequences. (Running on oeis4.)