

A048992


Hannah Rollman's numbers: the numbers excluded from A048991.


13



12, 23, 31, 34, 41, 42, 45, 51, 52, 53, 56, 61, 62, 63, 64, 67, 71, 72, 73, 74, 75, 78, 81, 82, 83, 84, 85, 86, 89, 91, 92, 93, 94, 95, 96, 97, 98, 101, 111, 113, 121, 122, 123, 131, 141, 151, 161, 171, 181, 191, 192, 201, 202, 210, 211, 212, 213, 214, 215, 216, 217
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

A116700 is a similar sequence. Note that 21 is missing from the current sequence, because we deleted 12 in computing A048991 and now 21 is no longer "earlier in the sequence". On the other hand 21 is present in A116700.  N. J. A. Sloane, Aug 05 2007
Otherwise said: Numbers which occur in the concatenation of all smaller numbers not listed in this sequence.  M. F. Hasler, Dec 29 2012
Number of terms < 10^n, n = 1, 2, ...: (0, 37, 589, 7046, ...), gives number of ndigit terms as first differences: (37, 552, 6457, ...).  M. F. Hasler, Oct 25 2019


LINKS



MATHEMATICA

a[0] = 1; s = "1"; a[n_] := a[n] = For[k = a[n1] + 1, True, k++, If[StringFreeQ[s, t = ToString[k]], s = s <> t, Return[k]]]; Table[a[n], {n, 1, 100}] (* JeanFrançois Alcover, Nov 25 2013 *)


PROG

(Python) # see Hobson link
(Haskell)
import Data.List (isInfixOf)
a048992 n = a048992_list !! (n1)
a048992_list = g [1..] [] where
g (x:xs) ys  xs' `isInfixOf` ys = x : g xs ys
 otherwise = g xs (xs' ++ ys)
where xs' = reverse $ show x
(PARI) D=[]; for(n=1, 999, for(i=0, #D#d=digits(n), D[i+1..i+#d]!=d  print1(n", ")  next(2)); D=concat(D, d)) \\ M. F. Hasler, Oct 25 2019


CROSSREFS



KEYWORD



AUTHOR



EXTENSIONS



STATUS

approved



