login
A135759
Least Catalan number divisible by 2^n: a(n) = A000108(2^(n+1)-2).
1
1, 2, 132, 2674440, 3814986502092304, 24139737743045626825711458546273312, 2861304849265668492891140780463352404986232263244287143198790516197234752
OFFSET
0,2
COMMENTS
The next term has 150 digits. - Harvey P. Dale, Jan 09 2017
FORMULA
a(n) = C(2^(n+2)-4, 2^(n+1)-2) / (2^(n+1)-1).
MATHEMATICA
Table[Binomial[2^(n + 2) - 4, 2^(n + 1) - 2]/(2^(n + 1) - 1), {n, 0, 10}] (* G. C. Greubel, Nov 07 2016 *)
Table[SelectFirst[CatalanNumber[Range[300]], Divisible[#, 2^n]&], {n, 0, 7}] (* Harvey P. Dale, Jan 09 2017 *)
PROG
(PARI) {a(n) = binomial(2^(n+2)-4, 2^(n+1)-2) / (2^(n+1)-1)}
for(n=0, 8, print1(a(n), ", "))
CROSSREFS
Cf. A038003 (odd Catalan numbers).
Sequence in context: A186194 A099682 A214436 * A014315 A221468 A327911
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Dec 02 2007
STATUS
approved