OFFSET
0,1
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
W. Lang, Rationals r(n).
FORMULA
a(n) = numerator(r(n)), with the rationals defined above.
EXAMPLE
Rationals r(n): [3/2, 11/8, 23/16, 179/128, 365/256, 1439/1024, 2911/2048, 46147/32768,...]
MATHEMATICA
r[n_]:= 1+Sum[(-1/4)^k*CatalanNumber[k]/2, {k, 0, n}]; Numerator[Table[ r[n], {n, 0, 50}]] (* G. C. Greubel, Mar 27 2018 *)
PROG
(PARI) {r(n) = 1 + sum(k=0, n, (-1/4)^k*binomial(2*k, k)/(2*(k+1)))};
for(n=0, 30, print1(numerator(r(n)), ", ")) \\ G. C. Greubel, Mar 27 2018
(Magma) [Numerator(1 + (&+[(-1/4)^k*Binomial(2*k, k)/(2*(k+1)): k in [0..n]])): n in [0..30]]; // G. C. Greubel, Mar 27 2018
CROSSREFS
KEYWORD
nonn,easy,frac
AUTHOR
Wolfdieter Lang, Jul 20 2006
STATUS
approved