A140132 - OEIS

%I #16 Jun 25 2024 08:31:33

%S 0,1,2,6,7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,

%T 7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,7,8,3,4,

%U 5,9,10,11,6,7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,7,8,3,4,5,9,10,11,6,7

%N a(n) = Sum_digits{a(n-1)+a(n-2)+Sum_digits[a(n-1)]+Sum_digits[a(n-2)]}, with a(0)=0 and a(1)=1.

%C After the first three terms the sequence is periodic: 6,7,8,3,4,5,9,10,11.

%p P:=proc(n) local a,i,t; t:=[0,1]; for i from 1 to n do

%p a:=t[-2]+t[-1]+convert(convert(t[-2],base,10),`+`)+convert(convert(t[-1],base,10),`+`);

%p t:=[op(t),convert(convert(a,base,10),`+`)]; od; print(op(t)); end: P(93); # _Paolo P. Lava_, Jun 25 2024

%Y Cf. A016052, A047892, A047897, A047898, A047899, A047900, A047902, A047903, A055263, A134268, A135210, A140131.

%K easy,nonn,base

%O 0,3

%A _Paolo P. Lava_ and _Giorgio Balzarotti_, May 09 2008