A072546 Sequence related to Fibonacci and "tribonacci" sequences : let f(1)=1, f(2)=n, f(k+2)=f(k+1)+f(k), t(1)=t(2)=t(3)=1, t(k+3)=t(k+2)+t(k+1)+t(k) (t(k)=A000213(k-1)); sequence gives the smallest value k = a(n) such that t(k)>f(k).

6, 9, 12, 14, 15, 16, 18, 19, 19, 20, 21, 21, 22, 23, 23, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30, 30, 30, 31, 31, 31, 31, 31, 32, 32, 32, 32, 32, 32, 32, 33, 33, 33, 33, 33, 33, 33, 34, 34, 34, 34, 34, 34, 34, 34, 35, 35, 35, 35

Offset: 1

Author

Benoit Cloitre, Aug 05 2002

Keywords

• nonn

Crossrefs

Cf. A000045, A000213, A000204.

Formula

Asymptotically: a(n)= C*Log(n) + 0(Log(n)) with C a constant = 8.2... (this constant doesn't depend on initial values f(1), t(1), t(2), t(3) while f(2)=n )