A115034 Alternately multiply and divide, with a(1)=1 and a(2)=2.

1, 2, 2, 1, 2, 2, 4, 2, 8, 4, 32, 8, 256, 32, 8192, 256, 2097152, 8192, 17179869184, 2097152, 36028797018963968, 17179869184, 618970019642690137449562112, 36028797018963968

Offset: 1

Author

Giovanni Teofilatto, Feb 26 2006; corrected Feb 28 2006

Keywords

• easy
• nonn

Comments

a(n) = power of 2; taking the terms a(n+1)>=a(n), the sequence of exponent of power of 2 is 0,1,1,2,3,5,8,... which are the Fibonacci Numbers.

Crossrefs

Cf. A115033, A174348.

Programs

Mathematica

nxt[{a_, b_}]:={a*b, (a*b)/b}; NestList[nxt, {1,2}, 10]//Flatten (* Georg Fischer, Jun 18 2021 *)

Formula

a(2*k) = a(2*k-3); a(2*k+1) = a(2*k)*a(2*k-1) - Georg Fischer, Jun 18 2021

Extensions

Definition adapted to offset by Georg Fischer, Jun 18 2021