A093987 a(1) = 1, a(2) = 2, a(n+1) = a(n)^(2n)/ a(n-1). Symmetrically a(n) = {a(n-1)*a(n+1)}^[1/{(n-1) +(n+1)}].

1, 2, 16, 8388608, 1532495540865888858358347027150309183618739122183602176

Offset

1,2

Comments

The next term has 535 digits. - Harvey P. Dale, Jan 31 2020

Links

Table of n, a(n) for n=1..5.

Example

a(5) = 8388608^8/16 = 1.53249554e+54.
a(6) =~ 8.5173068734e+534.

Mathematica

a[1] = 1; a[2] = 2; a[n_] := a[n - 1]^(2n - 2)/a[n - 2]; Table[ a[n], {n, 6}] (* Robert G. Wilson v, May 24 2004 *)
RecurrenceTable[{a[1]==1, a[2]==2, a[n+1]==a[n]^(2n)/a[n-1]}, a, {n, 5}] (* Harvey P. Dale, Jan 31 2020 *)

Crossrefs

Cf. A093985, A093986.

Sequence in context: A258169 A325048 A068916 * A275588 A114560 A108883

Adjacent sequences: A093984 A093985 A093986 * A093988 A093989 A093990

Keyword

nonn

Author

Amarnath Murthy, May 22 2004

Extensions

Edited and extended by Robert G. Wilson v, May 24 2004

Status

approved