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A054755 Odd powers of primes of form q=x^2+1 (A002496). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A002496 is a subset, the odd power exponent is 1.

LINKS

Table of n, a(n) for n=1..42.

FORMULA

EulerPhi[a(n)]=[q^(2k)]*(q-1) and a(n)-EulerPhi[a(n)]=q^(2k), where q=1+x^2 and prime.

EXAMPLE

a(20) = 3125 = 5^5, q = 5 = 4^2+1 and Phi[3125] = 2500 = 50^2, 3125-Phi[3125] = 625 = 25x25.

CROSSREFS

Cf. A000010, A051953, A002496, A039770.

Sequence in context: A062318 A034445 A054754 * A093331 A162216 A032158

Adjacent sequences:  A054752 A054753 A054754 * A054756 A054757 A054758

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 25 2000

STATUS

approved

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Last modified December 20 17:19 EST 2014. Contains 252271 sequences.