The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A330828 The squares of the Fermat primes, (A019434(n))^2. 4
 9, 25, 289, 66049, 4295098369 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also the first element of the power-spectral basis of A330826.  The second element of the power-spectral basis of A330826 is A001146(n+1), n=0..4. LINKS FORMULA a(n) = A019434(n)^2. EXAMPLE a(1) = 3^2 = 9. The spectral basis of A330826(1) = 12 is {9,4}, consisting of primes and powers. MAPLE F := n -> 2^(2^n) + 1; a := proc(n) if isprime(F(n)) then return F(n)^2 fi; end; [seq(a(n)), n=0..4)]; CROSSREFS Cf. A000215, A001146, A019434, A330829. Sequence in context: A227891 A193065 A278911 * A201807 A228465 A048056 Adjacent sequences:  A330825 A330826 A330827 * A330829 A330830 A330831 KEYWORD nonn,hard,more AUTHOR Walter Kehowski, Jan 06 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 8 19:29 EDT 2020. Contains 336298 sequences. (Running on oeis4.)