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A091772
a(n) = gcd(A000108(n), A000110(n)).
1
1, 2, 5, 1, 2, 1, 1, 10, 1, 1, 2, 1, 1, 2, 5, 1, 6, 7, 1, 4, 3, 3, 2, 3, 37, 34, 47, 5, 68, 53, 11, 2, 1, 39, 14, 1, 1, 2, 1, 1, 4, 1, 77745, 4, 5, 5, 126, 51, 1, 6, 1, 1, 44, 1, 1, 12, 31, 1, 2, 3, 663, 46, 51, 5, 2, 41, 1, 4, 3, 5, 29318, 445, 3, 6, 1, 39, 4, 5, 31, 4, 5, 23, 2, 1
OFFSET
1,2
LINKS
MATHEMATICA
Table[GCD[CatalanNumber[n], BellB[n]], {n, 1, 84}] (* Amiram Eldar, Nov 23 2019 *)
PROG
(Python)
from itertools import count, accumulate, islice
def A091772_gen(): # generator of terms
yield 1
blist, b, c = (1, 2), 1, 1
for n in count(1):
blist = list(accumulate(blist, initial=(b:=blist[-1])))
yield gcd(b, c := c*(4*n+2)//(n+2))
A091772_list = list(islice(A091772_gen(), 20)) # Chai Wah Wu, Jun 22 2022
CROSSREFS
Cf. A000108 (Catalan numbers), A000110 (Bell Numbers).
Sequence in context: A197737 A189824 A197814 * A275479 A075790 A240543
KEYWORD
nonn
AUTHOR
Jon Perry, Mar 06 2004
STATUS
approved