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A236250
Period of the n-th convergent to the continued fraction expansion of Pi.
1
1, 6, 13, 112, 51, 24, 15088, 12284, 88460, 1204, 459, 31824, 93210, 1864254, 531648, 456036, 8299090, 28574910, 1813560, 32552820, 33166008, 133585180, 2503410, 214098720, 3183870690, 7411133309730, 4852769490690, 2294509753536, 175964053944, 3336533898768
OFFSET
1,2
FORMULA
a(n) = A007732(A002486(n+2)). - Michel Marcus, Jan 21 2014
EXAMPLE
The 2nd convergent is 22/7 = 3.142857 142857 ..., whose period is 6, so a(2) = 6.
The 3rd convergent is 333/106 = 3.1 4150943396226 4150943396226 ..., whose period is 13, so a(3) = 13.
PROG
(Sage)
st_clenov = 30
def A236250(n) :
vu = continued_fraction_list(pi, nterms=st_clenov);
p = []
for i in (0..n) :
p.append(convergents(vu)[i].period())
return(p)
A236250(st_clenov-1);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jani Melik, Jan 21 2014
STATUS
approved