The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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)}]. 0
 1, 2, 16, 8388608, 1532495540865888858358347027150309183618739122183602176 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The next term has 535 digits. - Harvey P. Dale, Jan 31 2020 LINKS 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 10 19:52 EDT 2020. Contains 336381 sequences. (Running on oeis4.)