A020666 a(n)^n is the least n-th power containing every digit.

1023456789, 32043, 2326, 763, 309, 159, 56, 104, 49, 36, 25, 15, 25, 17, 17, 15, 16, 7, 5, 6, 6, 5, 11, 9, 14, 5, 5, 5, 5, 9, 5, 8, 11, 4, 4, 6, 5, 7, 3, 5, 4, 4, 6, 4, 3, 6, 3, 3, 4, 4, 5, 4, 3, 6, 4, 4, 3, 4, 4, 3, 3, 3, 3, 3, 3, 4, 3, 2, 3, 2, 3, 3, 3, 3, 4, 3, 3, 3, 2, 3, 4, 2, 3, 2, 3, 3, 2, 2, 2

Offset

1,1

Comments

It is extremely probable that a(n) = 2 for all n >= 169.

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Prog

(Python)
def a(n):
    if n == 1: return 1023456789
    an = 2
    while not(len(set(str(an**n))) == 10): an += 1
    return an
print([a(n) for n in range(1, 90)]) # Michael S. Branicky, Jul 04 2021

Crossrefs

Cf. A020667, A112388, A137214.

Sequence in context: A269120 A095733 A239919 * A074205 A277054 A218770

Adjacent sequences: A020663 A020664 A020665 * A020667 A020668 A020669

Keyword

nonn,base

Author

David W. Wilson

Status

approved