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A054755
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Odd powers of primes of form q=x^2+1 (A002496).
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1
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2, 5, 8, 17, 32, 37, 101, 125, 128, 197, 257, 401, 512, 577, 677, 1297, 1601, 2048, 2917, 3125, 3137, 4357, 4913, 5477, 7057, 8101, 8192, 8837, 12101, 13457, 14401, 15377, 15877, 16901, 17957, 21317, 22501, 24337, 25601, 28901, 30977, 32401
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OFFSET
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1,1
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COMMENTS
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A002496 is a subset, the odd power exponent is 1.
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LINKS
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Table of n, a(n) for n=1..42.
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FORMULA
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EulerPhi[a(n)]=[q^(2k)]*(q-1) and a(n)-EulerPhi[a(n)]=q^(2k), where q=1+x^2 and prime.
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EXAMPLE
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a(20) = 3125 = 5^5, q = 5 = 4^2+1 and Phi[3125] = 2500 = 50^2, 3125-Phi[3125] = 625 = 25x25.
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CROSSREFS
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Cf. A000010, A051953, A002496, A039770.
Sequence in context: A112346 A034445 A054754 * A093331 A162216 A032158
Adjacent sequences: A054752 A054753 A054754 * A054756 A054757 A054758
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Apr 25 2000
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STATUS
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approved
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