OFFSET
1,1
COMMENTS
Also the least odd prime number m such that m divides floor(n/m) or m>n.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(3)=5, since binomial(3+5,5) mod 5 = 56 mod 5 = 1 and 5 is the minimal odd prime number with this property.
a(8)=11 because of binomial(8+11,11)=75582=6871*11+1, but binomial(8+k,k) mod k<>1 for all odd primes <11.
MATHEMATICA
With[{oprs=Rest[Prime[Range[100]]]}, Flatten[Table[Select[oprs, Mod[ Binomial[ n+#, #], #]==1&, 1], {n, 90}]]] (* Harvey P. Dale, Jun 27 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Hieronymus Fischer, Oct 20 2007
STATUS
approved