%I #6 Mar 30 2012 18:39:15
%S 1,4,7,10,12,15,18,21,24,27,30,32,35,38,41,44,47,50,52,55,58,61,64,67,
%T 70,72,75,78,81,84,87,90,92,95,98,101,104,107,110,112,115,118,121,124,
%U 127,130,132,135,138,141,144,147,150,152,155,158,161,164,167,170,172
%N a(1)=1, then a(n)=a(n-1)+2 if the final decimal digit of a(n) is 0, a(n)=a(n-1)+3 otherwise.
%F 7*a(n)-20*n is a periodic sequence with period (12, 11, 10, 16, 15, 14, 13, 12, 11, 10, 16, 15, 14, 13) of length 14.
%K nonn,base
%O 1,2
%A _Benoit Cloitre_, Mar 08 2003