A061381 Smallest "inconsummate number" in base n greater than in the previous base.

13, 17, 29, 46, 64, 86, 105, 136, 161, 200, 229, 276, 309, 362, 419, 460, 505, 572, 621, 694, 749, 830, 889, 978, 1054, 1136, 1205, 1306, 1381, 1490, 1569, 1684, 1769, 1892, 1999, 2112, 2205, 2342, 2441, 2584, 2689, 2840, 2949, 3106, 3269, 3386, 3505, 3678

Offset

2,1

Links

Chai Wah Wu, Table of n, a(n) for n = 2..226

Mathematica

n = 1; Do[ While[k = n; While[ Apply[ Plus, IntegerDigits[k, b] ]*n != k && k < 100n, k += n]; k != 100n, n++ ]; Print[n], {b, 2, 60} ]

Prog

(Python)
from functools import lru_cache
from itertools import count, combinations_with_replacement
from sympy.ntheory import digits
@lru_cache(maxsize=None)
def A061381(n):
    for k in count((0 if n <= 2 else A061381(n-1))+1):
        for l in count(1):
            if (n-1)*l*k < n**(l-1):
                return k
            for d in combinations_with_replacement(range(n), l):
                if (s:=sum(d)) > 0 and sorted(digits(s*k, n)[1:]) == list(d):
                    break
            else:
                continue
            break # Chai Wah Wu, May 09 2023

Crossrefs

Cf. A052491.

Sequence in context: A079348 A349667 A174024 * A048520 A283407 A283358

Adjacent sequences: A061378 A061379 A061380 * A061382 A061383 A061384

Keyword

base,easy,nice,nonn

Author

Robert G. Wilson v, Jun 08 2001

Status

approved