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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.
2
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
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
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
KEYWORD
nonn
AUTHOR
Marina Ibrishimova, Feb 27 2016
EXTENSIONS
More terms from Michael De Vlieger, Feb 28 2016
STATUS
approved