A211770 - OEIS

%I #7 Jan 10 2024 15:49:26

%S 1234567890,24680,3692581470,48260,50,62840,7418529630,86420,

%T 9876543210,0,1234567890,24680,3692581470,48260,50,62840,7418529630,

%U 86420,9876543210,0,1234567890,24680,3692581470,48260,50,62840,7418529630,86420,9876543210,0

%N  a(n) = concatenation of periods of periodic sequences of ending digits of multiples of n.

%C  Periodic sequence with period {1234567890, 24680, 3692581470, 48260, 50, 62840, 7418529630, 86420, 9876543210, 0}.

%F  a(n) = a(10*k + n) for k = 1, 2, 3, …

%e  For n = 3; multiples of 3: 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,…; ending digits: 3,6,9,2,5,8,1,4,7,0,3,6,9,2,…; period: 3,6,9,2,5,8,1,4,7,0; concatenation of period: 3692581470.

%t PadRight[{},40,{1234567890,24680,3692581470,48260,50,62840,7418529630,86420,9876543210,0}] (* _Harvey P. Dale_, Jan 10 2024 *)

%K nonn,base

%O 1,1

%A _Jaroslav Krizek_, Apr 26 2012