cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A353010 a(n) = maximal d such that Product_{k=0..m} binomial(m,k) is divisible by m^(m+d), where m = A276710(n).

Original entry on oeis.org

0, 0, 3, 0, 1, 9, 49, 0, 21, 19, 31, 73, 0, 61, 57, 16, 4, 46, 13, 43, 25, 0, 20, 106, 1, 57, 172, 81, 43, 66, 25, 29, 51, 41, 38, 140, 80, 1, 71, 0, 0, 34, 117, 59, 199, 134, 208, 181, 9, 55, 259, 202, 114, 28, 263, 100, 145, 32, 157, 217, 60, 121, 36, 73, 86, 94, 19, 67, 154, 21, 40, 73, 57, 167, 392, 135, 256
Offset: 1

Views

Author

Hagen von Eitzen, Apr 15 2022

Keywords

Comments

By definition of A276710, a(n) >= -1.
It is conjectured that a(n) >= 0, computationally verified up to n = 10^7.
Empirically from terms up to n=10^7, a(n) seems to become quite large, small values are rare, and yet a(n)=0 also seems to occur for large n.

Examples

			The 7th term of A276710 is 105 because Product_{k=1..105} binomial(36,k) is divisible by 105^(105-1). Actually, it is divisible by 105^(105+49), but not by 105^(105+50). Therefore, a(7) = 49.
		

Crossrefs

Cf. A276710.

Programs

  • Python
    from math import prod, comb
    from itertools import islice
    from sympy import nextprime
    def A353010_gen(): # generator of terms
        p, q = 3, 5
        while True:
            for m in range(p+1,q):
                r = m**(m-1)
                c = 1
                for k in range(m+1):
                    c = c*comb(m,k) % r
                if c == 0:
                    d, (e, f) = -m, divmod(prod(comb(m,k) for k in range(m+1)),m)
                    while f == 0:
                        d += 1
                        e, f = divmod(e,m)
                    yield d
            p, q = q, nextprime(q)
    A353010_list = list(islice(A353010_gen(),40)) # Chai Wah Wu, Jun 09 2022