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A104804 "Rounded hypotenuses": a(n) = round(sqrt(a(n-1)^2 + a(n-2)^2)), a(1)=1, a(2)=3. 7
1, 3, 3, 4, 5, 6, 8, 10, 13, 16, 21, 26, 33, 42, 53, 68, 86, 110, 140, 178, 226, 288, 366, 466, 593, 754, 959, 1220, 1552, 1974, 2511, 3194, 4063, 5168, 6574, 8362, 10637, 13530, 17211, 21892, 27847, 35422, 45057, 57314, 72904, 92736, 117962, 150050 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(n) = A063827(n) for n > 2. - Georg Fischer, Oct 07 2018
MATHEMATICA
a[n_] := a[n] = Round[ Sqrt[ a[n - 1]^2 + a[n - 2]^2]]; a[1] = 1; a[2] = 3; Table[ a[n], {n, 48}] (* Robert G. Wilson v, Mar 28 2005 *)
PROG
(Python)
from gmpy2 import isqrt_rem
A104804_list = [1, 3]
for _ in range(1000):
i, j = isqrt_rem(A104804_list[-1]**2+A104804_list[-2]**2)
A104804_list.append(int(i+ int(4*(j-i) >= 1))) # Chai Wah Wu, Aug 16 2016
CROSSREFS
Sequence in context: A327226 A011977 A104803 * A240207 A347286 A144489
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 26 2005
EXTENSIONS
More terms from Robert G. Wilson v, Mar 28 2005
STATUS
approved

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Last modified April 20 00:03 EDT 2024. Contains 371798 sequences. (Running on oeis4.)