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A125227
A014741(n)/6 for n>2.
2
1, 3, 7, 9, 21, 27, 49, 57, 63, 81, 147, 171, 189, 219, 243, 301, 343, 399, 441, 513, 567, 657, 729, 889, 903, 1029, 1083, 1197, 1323, 1533, 1539, 1701, 1971, 2107, 2187, 2359, 2401, 2667, 2709, 2793, 3087, 3249, 3591, 3969, 4161, 4401, 4599, 4617, 5103, 5913
OFFSET
3,2
COMMENTS
A014741(n) is divisible by 6 for n>2.
All powers of 3 are terms. All powers of 7 are terms. The prime divisors of terms of this sequence (for n up to 10^6) in order of their first appearance are 3, 7, 19, 73, 43, 127, 337, 163, 379, 571, 5419, 487, 2593, 439, 1459, 431, 883.
The sequence is multiplicative in the sense that if two numbers k and m are terms, then k*m is too.
LINKS
FORMULA
a(n) = A014741(n)/6 = A014945(n-1)/3. - Max Alekseyev, Nov 14 2012
EXAMPLE
a(3) = A014741(3)/6 = 6/6 = 1.
a(4) = A014741(4)/6 = 18/6 = 3.
MATHEMATICA
Select[Range[3, 6000], PowerMod[2, #+1, # ]==2&]/6
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Jan 15 2007
STATUS
approved