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A020743
Pisot sequence L(7,10).
3
7, 10, 15, 23, 36, 57, 91, 146, 235, 379, 612, 989, 1599, 2586, 4183, 6767, 10948, 17713, 28659, 46370, 75027, 121395, 196420, 317813, 514231, 832042, 1346271, 2178311, 3524580, 5702889, 9227467, 14930354, 24157819, 39088171, 63245988, 102334157, 165580143
OFFSET
0,1
FORMULA
a(n) = Fib(n+5)+2 = A157725(n+5). a(n) = 2a(n-1) - a(n-3).
MATHEMATICA
LinearRecurrence[{2, 0, -1}, {7, 10, 15}, 40] (* Harvey P. Dale, Jun 10 2022 *)
PROG
(PARI) pisotL(nmax, a1, a2) = {
a=vector(nmax); a[1]=a1; a[2]=a2;
for(n=3, nmax, a[n] = ceil(a[n-1]^2/a[n-2]));
a
}
pisotL(50, 7, 10) \\ Colin Barker, Aug 07 2016
CROSSREFS
Subsequence of A018910. See A008776 for definitions of Pisot sequences.
Cf. A020717.
Sequence in context: A155716 A025002 A120136 * A088350 A083390 A234093
KEYWORD
nonn,easy
STATUS
approved