OFFSET
1,1
COMMENTS
Inspired by Ramanujan's infinite nested radical of natural numbers.
REFERENCES
Ramanujan's 2nd Notebook, Chapter XII, Page 108, entry 4.
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 1..10001
EXAMPLE
2.4946251475410092901872271300040774512687733667084139614755923004434339649...
MATHEMATICA
RealDigits[Chop[N[-I*Fold[#2*Sqrt[1 + #1*I] &, 0, Reverse[Range[400]]], 125]], 10, 120][[1]] (* Vaclav Kotesovec, Dec 22 2018 *)
PROG
(PARI)
b(n) = imag(fold((x, y)->sqrt(1+x*y), Vecrev([2..n+1])*I));
N=106; default(realprecision, N); limitnum(b, , 4) \\ Gheorghe Coserea, Dec 23 2018
CROSSREFS
KEYWORD
cons,nonn
AUTHOR
Robert G. Wilson v, Dec 15 2018
STATUS
approved