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A361669
a(n) = floor of sinh(sinh(sinh(...(1)...))) with n iterations.
0
1, 1, 1, 2, 3, 22, 3355531547
OFFSET
0,4
COMMENTS
a(7) = ~2.67*10^1457288834.
sinh(x) = (e^x - e^-x)/2 is dominated by e^x as x tends to infinity, meaning that the sequence grows tetrationally.
LINKS
Eric Weisstein's World of Mathematics, Hyperbolic Sine.
EXAMPLE
a(0) = 1,
a(1) = floor(sinh(1)) = floor(1.175...) = 1,
a(2) = floor(sinh(sinh(1))) = floor(1.465...) = 1,
a(3) = floor(sinh(sinh(sinh(1)))) = floor(2.048...) = 2,
a(4) = floor(sinh(sinh(sinh(sinh(1))))) = floor(3.812...) = 3,
a(5) = floor(sinh(sinh(sinh(sinh(sinh(1)))))) = floor(22.627...) = 22,
a(6) = floor(sinh(sinh(sinh(sinh(sinh(sinh(1))))))) = 3355531547.
MAPLE
a:= n-> floor(evalf((sinh@@n)(1), 45)):
seq(a(n), n=0..6); # Alois P. Heinz, Mar 20 2023
MATHEMATICA
Table[Floor[Nest[Sinh[n], 1, n]], {n, 0, 7}]
CROSSREFS
Sequence in context: A137077 A046965 A119679 * A191648 A130846 A114101
KEYWORD
nonn,easy
AUTHOR
Sylvia Zevi Abrams, Mar 20 2023
STATUS
approved