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A330824
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Numbers of the form 2^(2*p), where p is a Mersenne exponent, A000043.
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4
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OFFSET
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1,1
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COMMENTS
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Also the second element of the power-spectral basis of A064591. The first element of the power-spectral basis of A064591 is A133049.
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LINKS
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FORMULA
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EXAMPLE
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a(1) = 2^(2*2) = 16. Also A133049(1) = 3^2 = 9, and the spectral basis of A064591(1) = 24 is {9, 16}, consisting of primes and powers.
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MAPLE
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a := proc(n) if isprime(2^n-1) then return 2^(2*n) fi; end;
[seq(a(n), n=1..31)]; # ithprime(31) = 127
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MATHEMATICA
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2^(2*MersennePrimeExponent[Range[10]]) (* Harvey P. Dale, Jun 27 2023 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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