cp's OEIS Frontend

A352927 Numbers whose digits are nonzero, consecutive, and all increasing or all decreasing.

%I A352927 #21 Jul 09 2025 04:58:49
%S A352927 1,2,3,4,5,6,7,8,9,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,98,
%T A352927 123,234,321,345,432,456,543,567,654,678,765,789,876,987,1234,2345,
%U A352927 3456,4321,4567,5432,5678,6543,6789,7654,8765,9876,12345,23456,34567,45678,54321,56789,65432,76543,87654,98765,123456,234567,345678
%N A352927 Numbers whose digits are nonzero, consecutive, and all increasing or all decreasing.
%C A352927 There are 81 terms, corresponding to numbers that start with i and end with j, for 1 <= i <= 9, 1 <= j <= 9. - _Michael S. Branicky_, May 01 2022
%H A352927 Michael S. Branicky, <a href="/A352927/b352927.txt">Table of n, a(n) for n = 1..81</a>
%t A352927 Join[Range[9],Select[Range[350000],DigitCount[#,10,0]==0&&(Union[Differences[IntegerDigits[ #]]]=={1}||Union[Differences[IntegerDigits[#]]]=={-1})&]] (* _Harvey P. Dale_, Aug 13 2023 *)
%o A352927 (Python)
%o A352927 def sgn(n): return 1 if n >= 0 else -1
%o A352927 def afull(): return sorted(int("".join(map(str, range(i, j+sgn(j-i), sgn(j-i))))) for i in range(1, 10) for j in range(1, 10))
%o A352927 print(afull()) # _Michael S. Branicky_, May 01 2022
%Y A352927 Cf. A033075, A082927, A138141, A215014.
%K A352927 nonn,base,fini,full
%O A352927 1,2
%A A352927 _N. J. A. Sloane_, May 01 2022, following a suggestion from Ralph Sieber