cp's OEIS Frontend

A322511 Nonnegative numbers whose digits can be formed by typing adjacent keys on a 123-456-789 keypad without repeating a digit and without changing direction.

%I A322511 #10 Jan 07 2019 14:31:11
%S A322511 1,2,3,4,5,6,7,8,9,12,14,21,23,25,32,36,41,45,47,52,54,56,58,63,65,69,
%T A322511 74,78,85,87,89,96,98,123,147,258,321,369,456,654,741,789,852,963,987
%N A322511 Nonnegative numbers whose digits can be formed by typing adjacent keys on a 123-456-789 keypad without repeating a digit and without changing direction.
%C A322511 Subsequence of A280593.
%C A322511 Diagonal moves are not allowed.
%e A322511 The keypad is:
%e A322511 +---+---+---+
%e A322511 | 1 | 2 | 3 |
%e A322511 +---+---+---+
%e A322511 | 4 | 5 | 6 |
%e A322511 +---+---+---+
%e A322511 | 7 | 8 | 9 |
%e A322511 +---+---+---+
%e A322511 258 can be formed in a straight line, while 256 cannot, even though 256 is formed with adjacent digits. Therefore 258 is a part of this sequence while 256 is not.
%Y A322511 Cf. A280593, A280594, A280595, A281942.
%K A322511 nonn,full,fini,base
%O A322511 1,2
%A A322511 _Jason Jewell_, Dec 13 2018