OFFSET
1,2
LINKS
PROG
(Scheme)
(define (SBtree_index m n) (let loop ((m m) (n n) (z 1)) (cond ((= m n) z) ((< m n) (loop m (- n m) (+ z z))) (else (loop (- m n) n (+ z z 1))))))
(PARI)
SBtree_index(r) = { my(m=numerator(r), n=denominator(r), z=1); while(m!=n, if(m<n, n-=m; z<<=1, m-=n; z<<=1; z++)); (z); };
A273672(n) = { n=factor(n); n[, 2] = apply(A065620, n[, 2]); SBtree_index(factorback(n)); }; \\ Antti Karttunen, Mar 07 2020, based also on M. F. Hasler's code in A270418 and A270419
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 27 2016
STATUS
approved