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A269847
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Permutation of natural numbers: a(1) = 1, for n > 1, if n is an odd prime, a(n) = A003961(a(A000720(n))), otherwise a(n) = 2*a(n-A000720(n)).
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4
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1, 2, 3, 4, 5, 6, 9, 8, 10, 12, 7, 18, 15, 16, 20, 24, 25, 14, 27, 36, 30, 32, 21, 40, 48, 50, 28, 54, 45, 72, 11, 60, 64, 42, 80, 96, 75, 100, 56, 108, 35, 90, 81, 144, 22, 120, 63, 128, 84, 160, 192, 150, 135, 200, 112, 216, 70, 180, 49, 162, 33, 288, 44, 240, 126, 256, 125, 168, 320, 384, 225, 300, 105, 270, 400
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OFFSET
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1,2
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LINKS
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FORMULA
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a(1) = 1, and for n > 1, if n is an odd prime, a(n) = A003961(a(A000720(n))), otherwise [when n is 2 or composite] a(n) = 2*a(n-A000720(n)).
Declarative definition:
As a composition of other permutations:
Other identities. For all n >= 1:
a(A007097(n)) = A000040(n). [Maps the terms of primeth recurrence to primes.]
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PROG
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(Scheme, with memoization-macro definec)
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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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