login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A256112 Pandigitals in some base b (A061845) with an extra property: each number formed by the first i digits is divisible by i (digits in the pandigital base b) for 1 <= i <= b-1. 2
2, 19, 75, 99, 108, 135, 228, 2102, 8525, 10535, 13685, 13710, 26075, 31835, 44790, 203367, 247215, 477543, 518703, 576495, 620343, 743823, 3850399, 6996535, 6996871, 6996920, 7375543, 8947631, 11128712, 12306056, 78473956, 89789620, 156414388, 222029284, 306600196 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A111456 is the subsequence of terms divisible by the considered base (which is the least b such b^b > a(n)).

Is it true that there are no terms for base b > 16 and b even?

LINKS

Hans Havermann and Giovanni Resta, Table of n, a(n) for n = 1..233 (first 163 terms from Chai Wah Wu)

Hans Havermann, base-formatted (a=10, b=11, c=12, ..) terms, A111456 highlighted

EXAMPLE

247215 = 2046513[7] (i.e., in base 7) is pandigital and 20[7] = 14 is even, 204[7] = 102 is divisible by 3, etc. up to 204651[7] = 35316 which is divisible by 6.

In contrast to A111456, the number as a whole does not need to be divisible by the considered base. - M. F. Hasler, May 27 2020

PROG

(Python)

def dgen(n, b):

    if n == 1:

        t = list(range(b))

        for i in range(1, b):

            u = list(t)

            u.remove(i)

            yield i, u

    else:

        for d, v in dgen(n-1, b):

            for g in v:

                k = d*b+g

                if not k % n:

                    u = list(v)

                    u.remove(g)

                    yield k, u

A256112_list = lambda n: [a*k+b[0] for k in range(2, n) for a, b in dgen(k-1, k)]

print(A256112_list(10))

CROSSREFS

Cf. A111456.

Sequence in context: A110050 A219121 A054209 * A272053 A317274 A226019

Adjacent sequences:  A256109 A256110 A256111 * A256113 A256114 A256115

KEYWORD

nonn,base

AUTHOR

Chai Wah Wu, Jun 07 2015

EXTENSIONS

Edited by M. F. Hasler, May 27 2020

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 13 07:51 EDT 2021. Contains 342935 sequences. (Running on oeis4.)