A089969 Numbers n such that for increasing b the numbers of zeros in base b representation of n are monotonically decreasing, 1<b<n.

1, 2, 4, 5, 6, 9, 11, 13, 19, 23, 43, 47, 59, 61, 97, 137, 139, 157, 277, 281, 283, 311, 313, 317, 421, 431, 619, 673, 821, 823, 827, 829, 947, 997, 1151, 1663, 1993, 1997, 2383, 3359, 6229, 11437, 11443, 11447, 12899, 12911, 12917, 12919, 12923, 18367

Offset

1,2

Comments

Complement of A089970.

Links

Table of n, a(n) for n=1..50.

Example

m=9: '1001'[2] = '100'[3] = '21'[4] = '14'[5] = '13'[6] = '12'[7]
= '11'[8], 9 is a term, as number of zeros never increase.
m=10: 10 is not a term, as in base 5 there is 1 zero more than in
base 4: '1010'[2] = '101'[3] = '22'[4] = '20'[5].

Crossrefs

Sequence in context: A047315 A125881 A287370 * A166944 A073894 A341496

Adjacent sequences: A089966 A089967 A089968 * A089970 A089971 A089972

Keyword

nonn,base

Author

Reinhard Zumkeller, Nov 17 2003

Status

approved