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A056820
Euler totient function of Cullen numbers (A002064), n*2^n +1.
1
1, 2, 6, 20, 48, 132, 240, 528, 1364, 4180, 7560, 20784, 42768, 70992, 151632, 446208, 986880, 1688400, 4006800, 6080256, 13843440, 42125380, 79567488, 152712000, 292573440, 526051328, 797636448, 2942476992, 7257012896
OFFSET
0,2
LINKS
FORMULA
a(n) = A000010(A002064(n)). - Amiram Eldar, Nov 29 2019
MATHEMATICA
Table[ EulerPhi[ n*2^n + 1 ], {n, 1, 30} ]
CROSSREFS
Sequence in context: A139115 A193538 A121128 * A204422 A027558 A320910
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Aug 31 2000
STATUS
approved