OFFSET
1,1
COMMENTS
T(n) is the sum [last digit of a(n) + first digit of a(n+1)].
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..3999
EXAMPLE
The sequence starts with 21, 10, 1, 910, 11, 8, 2, 91, 71, 12, ...
Let's make the successive sums of [the last digit of a(n) + the first digit of a(n+1)]; we have [1+1] = 2; then [0+1] = 1; then [1+9] = 10; then [0+1] = 1; then [1+8] = 9; then [8+2] = 10; then [2+9] = 11; then [1+7] = 8; then [1+1] = 2; etc.
Those successive sums build the sequence T = 2, 1, 10, 1, 9, 10, 11, 8, 2, ... and T shows indeed the same succession of digits as the starting sequence.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Jean-Marc Falcoz, Aug 31 2018
STATUS
approved