

A322094


a(n) = number of occurrences of the decimal representation of n in the concatenation of all terms preceding a(n), or n if there are no such occurrences.


1



1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 1, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 1, 24, 25, 26, 27, 28, 29, 30, 1, 32, 33, 1, 35, 36, 37, 38, 39, 40, 1, 1, 43, 44, 1, 46, 47, 48, 49, 50, 1, 1, 1, 54, 55, 1, 57, 58, 59, 60, 1, 1, 1, 1, 65, 66, 1, 68, 69, 70, 1, 1
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OFFSET

1,2


COMMENTS

In the definition of the sequence, consider the number of occurrences of string s in string t to be the number of positions within t that have a perfect match with the digits in s. Thus the number of occurrences of 11 in 1111 is 3 and not 2.


LINKS

John Mason, Table of n, a(n) for n = 1..10000


EXAMPLE

a(12) is 1 as there is one occurrence of "12" in the string formed by concatenating a(1) through a(11).


MATHEMATICA

FromDigits /@ Nest[Function[{a, n}, Append[a, If[# == 0, IntegerDigits@ n, IntegerDigits@ #] &@ SequenceCount[Join @@ a, IntegerDigits@ n]]] @@ {#, Length@ # + 1} &, {{1}}, 67] (* Michael De Vlieger, Nov 26 2018 *)


CROSSREFS

Cf. A048991, A048992.
Sequence in context: A010881 A190600 A053832 * A056961 A297239 A043271
Adjacent sequences: A322091 A322092 A322093 * A322095 A322096 A322097


KEYWORD

nonn,base


AUTHOR

John Mason, Nov 26 2018


STATUS

approved



