Numbers in which starting from most significant digit the n-th digit is obtained by adding n to the (n-1)-st digit (the digit to the left of it) and then ignoring the carry. Alternately the n-th digit starting from the most significant digit is the n-th triangular number mod 10.
A069511
Numbers in which starting from most significant digit the n-th digit is obtained by adding n to the (n-1)-st digit (the digit to the left of it) and then ignoring the carry. Alternately the n-th digit starting from the most significant digit is the n-th triangular number mod 10.
Terms
- a(0) =1a(1) =13a(2) =136a(3) =1360a(4) =13605a(5) =136051a(6) =1360518a(7) =13605186a(8) =136051865a(9) =1360518655a(10) =13605186556a(11) =136051865568
External references
- oeis: A069511