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A372914
Decimal expansion of (3/13)*sqrt(3).
3
3, 9, 9, 7, 0, 4, 0, 3, 2, 5, 1, 5, 8, 9, 4, 7, 6, 0, 0, 4, 4, 7, 9, 5, 3, 0, 9, 5, 7, 8, 2, 7, 8, 2, 3, 8, 5, 2, 5, 2, 6, 2, 7, 5, 0, 8, 7, 9, 3, 1, 8, 6, 0, 6, 4, 7, 4, 4, 1, 6, 9, 9, 5, 2, 5, 8, 1, 3, 8, 3, 8, 8, 5, 1, 7, 4, 1, 5, 3, 9, 3, 1, 7, 2, 5, 7
OFFSET
0,1
FORMULA
Equals Sum_{k>=0} tan(k*Pi/3)/3^k.
EXAMPLE
0.39970403251589476004479530957827823852526275087931860...
MATHEMATICA
s = Sum[Tan[k Pi/3]/3^k, {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d]]
N[(3 Sqrt[3])/13, 100]
RealDigits[(3*Sqrt[3])/13, 10, 120][[1]] (* Harvey P. Dale, Jul 17 2024 *)
PROG
(Python)
from math import isqrt
def A372914(n): return isqrt(27*10**(n+1<<1)//169)%10 # Chai Wah Wu, Jul 08 2024
CROSSREFS
Sequence in context: A306963 A084762 A188444 * A201409 A111120 A100401
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Jul 01 2024
STATUS
approved