cp's OEIS Frontend

A098953 Slowest increasing sequence where each number is such that at least one pair of adjacent digits are consecutive, the first of the pair being the smaller.

%I A098953 #9 Dec 23 2021 08:34:38
%S A098953 12,23,34,45,56,67,78,89,101,112,120,121,122,123,124,125,126,127,128,
%T A098953 129,134,145,156,167,178,189,201,212,223,230,231,232,233,234,235,236,
%U A098953 237,238,239,245,256,267,278,289,301,312,323,334,340,341,342,343,344,345
%N A098953 Slowest increasing sequence where each number is such that at least one pair of adjacent digits are consecutive, the first of the pair being the smaller.
%C A098953 Corrected by Zak Seidov, Apr 15 2007
%H A098953 Michael S. Branicky, <a href="/A098953/b098953.txt">Table of n, a(n) for n = 1..10000</a>
%o A098953 (Python)
%o A098953 from itertools import count, islice
%o A098953 def cond(n):
%o A098953     d = list(map(int, str(n)))
%o A098953     return any(d[i+1] == d[i]+1 for i in range(len(d)-1))
%o A098953 def agen():
%o A098953     yield from filter(cond, count(1))
%o A098953 print(list(islice(agen(), 54))) # _Michael S. Branicky_, Dec 23 2021
%Y A098953 A similar sequence: A082927
%K A098953 base,easy,nonn
%O A098953 1,1
%A A098953 _Eric Angelini_, Oct 21 2004
%E A098953 a(51) and beyond from _Michael S. Branicky_, Dec 23 2021