A019479 Define the sequence S(a_0,a_1) by a_{n+2} is the least integer such that a_{n+2}/a_{n+1}>a_{n+1}/a_n for n >= 0. This is S(4,8).

4, 8, 17, 37, 81, 178, 392, 864, 1905, 4201, 9265, 20434, 45068, 99400, 219233, 483533, 1066465, 2352162, 5187856, 11442176, 25236513, 55660881, 122763937, 270764386, 597189652, 1317143240, 2905050865, 6407291381, 14131726001, 31168502866, 68744297112

Offset

0,1

Links

Colin Barker, Table of n, a(n) for n = 0..1000

D. W. Boyd, Linear recurrence relations for some generalized Pisot sequences, Advances in Number Theory ( Kingston ON, 1991) 333-340, Oxford Sci. Publ., Oxford Univ. Press, New York, 1993.

Index entries for Pisot sequences

Formula

Apparently satisfies a(n) = 3*a(n-1) - 2*a(n-2) + a(n-3) - a(n-4).

Empirical G.f.: (4-4*x+x^2-2*x^3)/(1-3*x+2*x^2-x^3+x^4). - Colin Barker, Feb 04 2012

Prog

(PARI) S(a0, a1, maxn) = a=vector(maxn); a[1]=a0; a[2]=a1; for(n=3, maxn, a[n]=a[n-1]^2\a[n-2]+1); a
S(4, 8, 40) \\ Colin Barker, Feb 16 2016

Crossrefs

Sequence in context: A215108 A307545 A115618 * A084814 A098125 A335274

Adjacent sequences: A019476 A019477 A019478 * A019480 A019481 A019482

Keyword

nonn

Author

R. K. Guy

Status

approved