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 A330820 Numbers of the form (M_p^2-1)^2, where M_p is a Mersenne prime, A000668. Also the second element of the power-spectral basis of A330817. 10
 64, 2304, 921600, 260112384, 4501400872550400, 295138898048817561600, 75557287266261531623424 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The first element of the power-spectral basis of A330817 is A330819. LINKS Table of n, a(n) for n=1..7. FORMULA a(n) = (A000668(n)^2-1)^2. EXAMPLE If n=1, a(1)=(3^2-1)^2=64. MAPLE A330820:=[]: for www to 1 do for i from 1 to 31 do #ithprime(31)=127 p:=ithprime(i); q:=2^p-1; if isprime(q) then x:=(q^2-1)^2; A330820:=[op(A330820), x] fi; od; od; A330820; MATHEMATICA Array[((2^MersennePrimeExponent[#] - 1)^2 - 1)^2 &, 10] (* Amiram Eldar, Jan 07 2020 *) CROSSREFS Cf. A000043, A000668, A330817, A330818, A330819. Sequence in context: A221424 A181241 A053107 * A000812 A240363 A239432 Adjacent sequences: A330817 A330818 A330819 * A330821 A330822 A330823 KEYWORD nonn AUTHOR Walter Kehowski, Jan 06 2020 STATUS approved

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Last modified May 30 06:53 EDT 2023. Contains 363045 sequences. (Running on oeis4.)