A385701 Numbers such that when the leftmost digit is moved to the unit's place the result is divisible by 6.

0, 6, 21, 24, 27, 42, 45, 48, 60, 63, 66, 69, 81, 84, 87, 201, 204, 207, 210, 213, 216, 219, 222, 225, 228, 231, 234, 237, 240, 243, 246, 249, 252, 255, 258, 261, 264, 267, 270, 273, 276, 279, 282, 285, 288, 291, 294, 297, 402, 405, 408, 411, 414, 417, 420, 423, 426, 429

Offset: 1

Author

Stefano Spezia, Jul 07 2025

Keywords

• nonn
• base
• easy
• look

Examples

			426 is a term since 264 = 44*6 is divisible by 6.
		

Links

• Stefano Spezia, Table of n, a(n) for n = 1..10000

Crossrefs

Similar sequences for k=1..9: A001477, A273892, A008585, A385700, A217398, this sequence, A385702, A385703, A008591.

Programs

Mathematica

Select[Range[0,430],Divisible[FromDigits[RotateLeft[IntegerDigits[#]]],6] &]

PARI

isok(k) = if (k==0, return(1)); my(d=digits(k), v = vector(#d-1, i, d[i+1])); v = concat(v, d[1]); fromdigits(v) % 6 == 0; \\ Michel Marcus, Jul 08 2025

Python

def ok(n): return int((s:=str(n))[1:]+s[0])%6 == 0
print([k for k in range(430) if ok(k)]) # Michael S. Branicky, Jul 08 2025