A239502 (Round(q^prime(n)) - 1)/prime(n), where q is the tribonacci constant (A058265).

4, 10, 74, 212, 1856, 5618, 53114, 1630932, 5161442, 167427844, 1729192432, 5577731626, 58401766802, 2005139696964, 69737304018266, 228184540445268, 8043367476888770, 86866463049858250, 285815985033409648, 10225367934387562098, 111384745483589787826

Offset

3,1

Comments

For n>=3, round(q^prime(n)) == 1 (mod 2*prime(n)). Proof in Shevelev link. In particular, all terms are even.

Links

Table of n, a(n) for n=3..23.

S. Litsyn and V. Shevelev, Irrational Factors Satisfying the Little Fermat Theorem, International Journal of Number Theory, vol.1, no.4 (2005), 499-512.

V. Shevelev, A property of n-bonacci constant, Seqfan (Mar 23 2014)

Eric Weisstein's World of Mathematics, Tribonacci Constant

Example

For n=3, q^5 = 21.049..., so a(3) = (21 - 1)/5 = 4.

Crossrefs

Cf. A007619, A007663, A238693, A238697, A238698, A238700, A058265.

Sequence in context: A244297 A207159 A152397 * A171754 A215872 A059919

Adjacent sequences: A239499 A239500 A239501 * A239503 A239504 A239505

Keyword

nonn

Author

Vladimir Shevelev and Peter J. C. Moses, Mar 20 2014

Status

approved