A023786 Katadromes: digits in base 4 are in strict descending order.

0, 1, 2, 3, 4, 8, 9, 12, 13, 14, 36, 52, 56, 57, 228

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• fini
• full
• easy

Comments

No more terms are possible because, although infinitely many numbers have base 4 digits in descending order, like 256, none beyond 228 can have them in strictly descending order. - Alonso del Arte, Feb 08 2019

Examples

			228 in base 4 is 3210. Since those digits are in strictly descending order, 228 is in the sequence.
229 in base 4 is 3211. Although those digits are in descending order, the repeated digit 1 means 229 is not in the sequence.
		

Crossrefs

Cf. A023760, A031999.

Programs

Mathematica

Select[Range[0, 255], Max[Differences[IntegerDigits[#, 4]]] < 0 &] (* Harvey P. Dale, Dec 15 2014 *)