The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A056821 Totient of the Woodall numbers (A003261), n*2^n -1. 1
 1, 6, 22, 36, 104, 382, 712, 1936, 4320, 6824, 15012, 46992, 79344, 183000, 421008, 480000, 1453784, 4658784, 8877792, 20958480, 38887680, 61284600, 110250264, 388201176, 719023536, 1734432480, 2889658368, 4745378304, 10350643968, 32212254718, 66251144568 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Amiram Eldar, Table of n, a(n) for n = 1..853 (terms 1..150 from Vincenzo Librandi) FORMULA a(n) = A000010(A003261(n)). MAPLE a:= n-> numtheory[phi](n*2^n-1): seq(a(n), n=1..35); # Alois P. Heinz, Apr 15 2019 MATHEMATICA Table[EulerPhi[n 2^n - 1], {n, 1, 35}] PROG (Magma) [EulerPhi(n*2^n-1): n in [1..30]]; // Vincenzo Librandi, Apr 15 2019 (PARI) a(n) = eulerphi(n*2^n -1); \\ Michel Marcus, Apr 15 2019 CROSSREFS Cf. A000010, A003261. Sequence in context: A046408 A123017 A264043 * A031083 A218015 A031305 Adjacent sequences: A056818 A056819 A056820 * A056822 A056823 A056824 KEYWORD nonn AUTHOR Robert G. Wilson v, Aug 31 2000 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 23 12:36 EDT 2023. Contains 365552 sequences. (Running on oeis4.)