This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A236402 #53 Mar 05 2024 11:28:37
%S A236402 0,1,2,3,4,5,6,7,8,9,10,20,30,40,50,60,70,80,90,100,101,102,103,104,
%T A236402 105,106,107,108,109,200,201,202,203,204,205,206,207,208,209,300,301,
%U A236402 302,303,304,305,306,307,308,309,400,401,402,403,404,405,406,407
%N A236402 Numbers with property that the sum of any pair of adjacent digits is a substring of the number.
%C A236402 This sequence has density 1, since all numbers except a thin fraction have digits 0 through 18 in base 100. In particular, there are at most x^0.99782 non-members up to x for large enough x. (This can be improved.) - _Charles R Greathouse IV_, Jan 30 2014
%C A236402 1263907548 is the smallest term that contains all ten digits. - _M. F. Hasler_, Jan 30 2014
%C A236402 Where does this first differ from A032945? - _R. J. Mathar_, Feb 03 2014
%C A236402 This first differs from A032945 at a(110)=910 (followed by 1000, 1001, 1002, ...) while A032945(110)=1000 (followed by 1010, 1020, 1030, ...). - _M. F. Hasler_, Dec 28 2014
%H A236402 T. D. Noe, <a href="/A236402/b236402.txt">Table of n, a(n) for n = 1..8495</a> (terms < 10^6)
%F A236402 a(n) ~ n. - _Charles R Greathouse IV_, Jan 30 2014
%e A236402 Examples of numbers in the sequence:
%e A236402 80 --> 8+0=8
%e A236402 107 --> 1+0=1 / 0+7=7
%e A236402 910 --> 9+1=10 / 1+0=1
%e A236402 1037 --> 1+0=1 / 0+3=3 / 3+7=10
%e A236402 1459 --> 1+4=5 / 4+5=9 / 5+9=14
%e A236402 41358 --> 4+1=5 / 1+3=4 / 3+5=8 / 5+8=13
%t A236402 fQ[n_] := Module[{d, p, s}, d = IntegerDigits[n]; p = Partition[d, 2, 1]; s = Plus @@@ p; Complement[s, Union[d, FromDigits /@ p]] == {}]; Join[Range[0, 9], Select[Range[10, 1000], fQ]] (* _T. D. Noe_, Jan 30 2014 *)
%o A236402 (PARI) is(n)=my(d=digits(n),S=Set(d),v=List(),t); for(i=2,#d, listput(v, 10*d[i-1]+d[i])); S=Set(concat(S,Vec(v))); for(i=2,#d, t=d[i-1]+d[i]; if(!setsearch(S, t), return(0))); 1 \\ _Charles R Greathouse IV_, Jan 13 2015
%o A236402 (Python)
%o A236402 def ok(n):
%o A236402 s = str(n)
%o A236402 return all(str(sum(map(int, s[i:i+2]))) in s for i in range(len(s)-1))
%o A236402 print(list(filter(ok, range(408)))) # _Michael S. Branicky_, Jun 11 2021
%Y A236402 Cf. A236403 (complement).
%Y A236402 Cf. A198298, A203565, A203566, A203569.
%K A236402 nonn,base,easy
%O A236402 1,3
%A A236402 _Eric Angelini_, Jan 30 2014