[seqfan] Sliding digit sums

[Eric Angelini]

Hello SeqFans,
Does S loop?
Start S with 1.
Now a(n) is the sum of the last "k" digits of S, "k" being the last digit of S augmented by 1.

S=1,1,2,4,8,16,23,12,6,21,3,12,6,15,15,18,29,...

Example:
S=1,... k=1+1=2; a(2)=0+1=1
S=1,1,... k=1+1=2; a(3)=1+1=2
S=1,1,2,... k=2+1=3; a(4)=1+1+2=4
S=1,1,2,4,... k=4+1=5; a(5)=0+1+1+2+4=8
S=1,1,2,4,8,... k=8+1=9; a(6)=0+1+1+2+4+8=16
S=1,1,2,4,8,16,... k=6+1=7; a(7)=1+1+2+4+8+1+6=23
S=1,1,2,4,8,16,23,... k=3+1=4; a(8)=1+6+2+3=12
S=1,1,2,4,8,16,23,12,... k=2+1=3; a(9)=3+1+2=6
S=1,1,2,4,8,16,23,12,6,... k=6+1=7; a(10)=1+6+2+3+1+2+6=21
S=1,1,2,4,8,16,23,12,6,21,... k=1+1=2, etc.

Best,
É.