OFFSET
0,3
LINKS
EXAMPLE
For n = 4:
- the first 5 terms of A002487 are: 0, 1, 1, 2, 1, 3,
- 0/1 + 1/1 + 1/2 + 2/1 + 1/3 = 23/6,
- so a(4) = 23.
PROG
(PARI) fusc(n)=local(a=1, b=0); while(n>0, if(bitand(n, 1), b+=a, a+=b); n>>=1); b \\ after Charles R Greathouse IV in A002487
{ s = 0; for (n=0, 44, print1 (numerator(s+=fusc(n)/fusc(n+1))", ")) }
(Python)
from fractions import Fraction
from functools import reduce
def A355075(n): return sum(Fraction(reduce(lambda x, y:(x[0], x[0]+x[1]) if int(y) else (x[0]+x[1], x[1]), bin(k)[-1:1:-1], (1, 0))[1], reduce(lambda x, y:(x[0], x[0]+x[1]) if int(y) else (x[0]+x[1], x[1]), bin(k+1)[-1:1:-1], (1, 0))[1]) for k in range(n+1)).numerator # Chai Wah Wu, Jun 19 2022
CROSSREFS
KEYWORD
AUTHOR
Rémy Sigrist, Jun 18 2022
STATUS
approved