A367607 - OEIS

%I #15 Dec 11 2023 23:10:25

%S 12,100,11,-1,110,22,102,120,101,112,201,111,122,211,121,210,221,202,

%T 220,1000,212,-1,1010,222,1002,1020,1001,1012,1100,1011,1022,1110,

%U 1021,1102,1120,1101,1112,1200,1111,1122,1210,1121,1202,1220,1201,1212,2001,1211,1222,2011,1221,2010,2021,2002,2020,2101,2012,2100

%N Comma-successor to n working in base 3, and written in base 3, or -1 if n has no successor.

%C This is a base-3 analog of A367338.

%H Michael S. Branicky, <a href="/A367607/b367607.txt">Table of n, a(n) for n = 1..10000</a>

%o (Python)

%o from sympy.ntheory.factor_ import digits

%o def a(n):

%o     b = n + 3*(n%3)

%o     return next((int("".join(map(str, d3))) for y in [1, 2] if (d3:=digits(b+y, 3)[1:])[0] == y), -1)

%o print([a(n) for n in range(1, 61)]) # _Michael S. Branicky_, Dec 11 2023

%Y Cf. A121085, A007089, A367338, A367355, A367356, A367606, A367608, A367609.

%K sign,base

%O 1,1

%A _N. J. A. Sloane_, Dec 11 2023