OFFSET
1,1
COMMENTS
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
Kevin Ryde, Proof of Wouter Meeussen's conjectured union
MAPLE
A019469:=n->`if`(binomial(2*n-4, n-2) mod n <> 0, n, NULL): seq(A019469(n), n=1..400); # Wesley Ivan Hurt, Sep 13 2014
MATHEMATICA
Select[Range[400], !Divisible[Binomial[2#-4, #-2], #]&] (* Harvey P. Dale, Aug 13 2015 *)
PROG
(PARI) valp(n, p)=my(s); while(n\=p, s+=n); s
bin(n, p)=valp(2*n, p)-2*valp(n, p)
is(n)=my(f=factor(n)); for(i=1, #f~, if(bin(n-2, f[i, 1])<f[i, 2], return(1))); 0 \\ Charles R Greathouse IV, Nov 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Name changed by Wesley Ivan Hurt, Sep 16 2014
STATUS
approved