A393718 The smallest number k such that the digit reversals of k, when written in all bases 2 to n, are strictly decreasing from base 2 to base n.

3, 33, 205, 900, 35161, 8450953, 137439474697

Offset

3,1

Links

Table of n, a(n) for n=3..9.

Formula

a(n) >= a(n-1).

Example

a(7) = 35161 as 35161 = 1000100101011001_2 = 1210020021_3 = 20211121_4 = 2111121_5 = 430441_6 = 204340_7 whose digit reversals are 1001101010010001_2 = 39569, 1200200121_3 = 33307, 12111202_4 = 25954, 1211112_5 = 22657, 144034_6 = 13846, 43402_7 = 10831, and 39569 > 33307 > 25954 > 22657 > 13846 > 10831.

Crossrefs

Cf. A393717, A393720, A393721, A393902, A393903, A305989, A305877, A004086.

Sequence in context: A195578 A370083 A382434 * A331193 A206950 A189644

Adjacent sequences: A393715 A393716 A393717 * A393719 A393720 A393721

Keyword

nonn,base,more

Author

Scott R. Shannon, Feb 26 2026

Status

approved