OFFSET
1,14
LINKS
Vladimir Shevelev, On divisibility of binomial(n-i-1,i-1) by i, Intl. J. of Number Theory, 3, no.1 (2007), 119-139.
PROG
(Sage)
def A178105(n):
return next((d for d in (2..n//2) if binomial(n-d-1, d-1) % d == 0 and gcd(n, d) > 1), 0)
# D. S. McNeil, Sep 05 2011
(PARI) a(n) = {my(md = -1); for (d=2, n\2, if (((binomial(n-d-1, d-1) % d) == 0) && (gcd(n, d) > 1), if (md == -1, md = d, md = min(d, md))); ); if (md == -1, 0, md); } \\ Michel Marcus, Feb 07 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, May 20 2010
EXTENSIONS
Corrected by R. J. Mathar, Sep 05 2011
STATUS
approved