Any digit "d" (except the first two) is the absolute difference between x and y -> x=sum of the 2 digits standing immediately to the left of "d", y=sum of the 2 digits standing immediately to the right of "d".

A102355

Any digit "d" (except the first two) is the absolute difference between x and y -> x=sum of the 2 digits standing immediately to the left of "d", y=sum of the 2 digits standing immediately to the right of "d".

Terms

    a(0) =0a(1) =1a(2) =2a(3) =120a(4) =121a(5) =201a(6) =2120a(7) =12120a(8) =121201a(9) =212012a(10) =12012120a(11) =12120121a(12) =20121201a(13) =212012120a(14) =1212012120a(15) =12120121201a(16) =21201212012

External references