A140602 Values of m for which C(m,k)+C(m,k+1)=C(m+1,k+1) divides C(m,2k+1) for some nonnegative integer k with 2k+1 <= m.

34, 89, 104, 359, 398, 2309, 2729, 3539, 4619, 8644, 14135, 36569, 255959

Offset

1,1

Comments

See A140601 which is the main entry for this sequence.

Some large terms of this sequence: 255959 (k=47), 618799 (k=25). - Max Alekseyev, Sep 19 2015

Links

Table of n, a(n) for n=1..13.

Example

a(1)=34 because C(34,6) + C(34,7) = 1344904 + 5379616 = 6724520 divides C(34,13) = 927983760.

Prog

(Sage)
for m in range(100000):
    for a in range(0, m//2):
        if (binomial(m, 2*a+1)%binomial(m+1, a+1) == 0):
            print(m); break  # Robin Visser, Oct 21 2023

Crossrefs

Cf. A140601, A140603.

Sequence in context: A086005 A169834 A248201 * A067977 A183311 A282811

Adjacent sequences: A140599 A140600 A140601 * A140603 A140604 A140605

Keyword

hard,more,nonn

Author

Andrew V. Sutherland, May 18 2008

Extensions

Offset corrected and a(12) added by Max Alekseyev, Aug 14 2017

a(13) from Robin Visser, Oct 21 2023

Status

approved