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A269452 phi(A157352(n)), n >= 1, where phi is Euler's totient function A000010, and A157352 gives the products of two distinct safe primes. 1
24, 40, 60, 88, 132, 184, 220, 232, 276, 348, 328, 460, 424, 492, 580, 636, 664, 712, 820, 1012, 904, 996, 1060, 1068, 1048, 1276, 1356, 1384, 1432, 1660, 1572, 1804, 1528, 1780, 1864, 1912, 2076, 2332, 2260, 2148, 2008, 2292, 2668, 2248, 2620, 2344, 2796, 2868, 3012, 2872, 3460, 3652, 3772, 3372 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

phi(p*q) = (p-1)(q-1) where p, q are distinct safe primes.

2^(a(n)/2) == 1 (mod A157352(n)). For the reference see a comment on A269454. - Wolfdieter Lang, Mar 31 2016

LINKS

Table of n, a(n) for n=1..54.

FORMULA

a(n) = phi(A157352(n)), n >= 1.

MATHEMATICA

EulerPhi /@ Select[Select[Range@ 4000, PrimeNu@ # == 2 &], Times @@ Map[If[PrimeQ[(# - 1)/2], #, 0] &, Map[First, FactorInteger@ #]] == # &] (* Michael De Vlieger, Feb 28 2016 *)

CROSSREFS

A000010, A157352, A269454.

Sequence in context: A043119 A039296 A043899 * A195562 A026040 A259217

Adjacent sequences:  A269449 A269450 A269451 * A269453 A269454 A269455

KEYWORD

nonn

AUTHOR

Marina Ibrishimova, Feb 27 2016

EXTENSIONS

More terms from Michael De Vlieger, Feb 28 2016

STATUS

approved

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Last modified May 24 07:19 EDT 2017. Contains 286939 sequences.