%I #21 Aug 03 2022 02:34:50
%S 1,2,3,4,5,6,7,8,9,101,202,212,303,313,323,404,414,424,434,505,515,
%T 525,535,545,606,616,626,636,646,656,707,717,727,737,747,757,767,808,
%U 818,828,838,848,858,868,878,909,919,929,939,949,959,969,979,989,2012
%N 1..9 followed by the canyon numbers A134970.
%C For n > 9 the structure of digits represents an abyss. The first digit is equal to the last digit (1  9). The first digits are in decreasing order. The last digits are in increasing order. The numbers only have one smallest digit. This sequence is finite. The final term is 9876543210123456789.
%C Superset of crater numbers (A193409). Subset of valley numbers (A193413).
%e Illustration using 654356:
%e 6 . . . . 6
%e . 5 . . 5 .
%e . . 4 . . .
%e . . . 3 . .
%Y Cf. A193409, A193413, A134970.
%K nonn,base,fini
%O 1,2
%A _Jaroslav Krizek_, Jul 25 2011
