A125227 A014741(n)/6 for n>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

Amiram Eldar, Table of n, a(n) for n = 3..10000

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

Cf. A014741, A000295, A086787.

Sequence in context: A056652 A014959 A057233 * A057286 A056745 A057263

Adjacent sequences: A125224 A125225 A125226 * A125228 A125229 A125230

Keyword

nonn

Author

Alexander Adamchuk, Jan 15 2007

Status

approved