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A130730 Fermat numbers of order 7 or F(n,7) = 2^(2^n)+7. 6
9, 11, 23, 263, 65543, 4294967303, 18446744073709551623, 340282366920938463463374607431768211463, 115792089237316195423570985008687907853269984665640564039457584007913129639943 (list; graph; refs; listen; history; text; internal format)



This sequence is equivalent to F(n)+ 6 or 2^(2^n)+ 1 + 6. This sequence does not appear to have any special divisibility properties. Fermat numbers of order 5 which are found in A063486, have the divisibility property if n is even, then 7 divides F(n,5). After the first 2 terms the ending digit is the same for all F(n,m) and is (6+m) mod 10.


Vincenzo Librandi, Table of n, a(n) for n = 0..11

Tigran Hakobyan, On the unboundedness of common divisors of distinct terms of the sequence a(n)=2^2^n+d for d>1, arXiv:1601.04946 [math.NT], 2016.


F(n,m): The n-th Fermat number of order m = 2^(2^n)+ m. The traditional Fermat numbers are F(n,1) or Fermat numbers of order 1 in this nomenclature.


Table[(2^(2^n) + 7), {n, 0, 15}] (* Vincenzo Librandi, Jan 09 2013 *)


(PARI) fplusm(n, m)= { local(x, y); for(x=0, n, y=2^(2^x)+m; print1(y", ") ) }

(Magma) [2^(2^n)+7: n in [0..11]]; // Vincenzo Librandi, Jan 09 2013


Cf. A063486, A130729.

Sequence in context: A103510 A233402 A276406 * A153697 A129399 A145790

Adjacent sequences: A130727 A130728 A130729 * A130731 A130732 A130733




Cino Hilliard, Jul 05 2007



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Last modified November 28 12:20 EST 2022. Contains 358416 sequences. (Running on oeis4.)