A368359 Comma transform of Catalan numbers.

11, 12, 25, 51, 44, 21, 24, 91, 4, 21, 65, 62, 27, 2, 9, 53, 1, 4, 1, 6, 2, 9, 3, 1, 44, 21, 26, 42, 1, 83, 41, 95, 82, 8, 43, 21, 24, 41, 6, 2, 1, 3, 1, 5, 2, 8, 3, 1, 5, 21, 67, 62, 21, 4, 41, 26, 22, 41, 4, 21, 66, 62, 29, 53, 1, 5, 2, 8, 3, 1, 5, 2, 7, 3, 1, 4, 1, 7, 2, 1, 4, 1, 6, 2, 1, 4, 1, 6, 2, 1, 3, 1, 6, 2, 9, 3, 1, 5, 2, 8

Offset

0,1

Comments

See A367360 for further information.

Links

Michael S. Branicky, Table of n, a(n) for n = 0..10000

Maple

C:= proc(n) option remember; binomial(2*n, n)/(n+1) end:
a:= n-> parse(cat(""||(C(n))[-1], ""||(C(n+1))[1])):
seq(a(n), n=0..99);  # Alois P. Heinz, Jan 03 2024

Prog

(Python)
from math import comb
def A368359(n): return 10*(comb(n<<1, n)//(n+1)%10)+int(str(comb(n+1<<1, n+1)//(n+2))[0]) # Chai Wah Wu, Jan 03 2024
(Python)
from itertools import count, islice, pairwise
def S(): # generator of Catalan numbers as strings
    C = 1
    for n in count(0):
        yield str(C)
        C = C*(4*n+2)//(n+2)
def agen(): yield from (int(t[-1]+u[0]) for t, u in pairwise(S()))
print(list(islice(agen(), 100))) # Michael S. Branicky, Jan 04 2024

Crossrefs

Cf. A000108, A367360.

Sequence in context: A042019 A221644 A022316 * A136433 A172173 A061760

Adjacent sequences: A368356 A368357 A368358 * A368360 A368361 A368362

Keyword

nonn,look,base

Author

N. J. A. Sloane, Jan 02 2024

Status

approved