OFFSET

1,2

COMMENTS

This is not A156819.

LINKS

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Eric Angelini, Talking to me?, personal blog, Feb 2024.

EXAMPLE

a(12) = 101 and the rightmost digit "1" is present in the next term ( 1)

a(13) = 1 and the rightmost digit "1" is present in the next term (11)

a(14) = 11 and the rightmost digit "1" is present in the next term (12)

a(15) = 12 and the rightmost digit "2" is present in the next term ( 2)

a(16) = 2 and the rightmost digit "2" is present in the next term (21)

a(17) = 21 and the rightmost digit "1" is present in the next term (13), etc.

MATHEMATICA

a[1]=0; a[n_]:=a[n]=(k=1; While[MemberQ[Array[a, n-1], k]|| FreeQ[IntegerDigits@k, Mod[a[n-1], 10]], k++]; k); Array[a, 79]

PROG

(Python)

from itertools import count, islice

def agen(): # generator of terms

an, aset, mink = 0, set(), 1

while True:

yield an

aset.add(an)

t, k = str(an%10), mink

an = next(k for k in count(mink) if k not in aset and t in str(k))

while mink in aset: mink += 1

print(list(islice(agen(), 79))) # Michael S. Branicky, Feb 18 2024

CROSSREFS

KEYWORD

base,nonn

AUTHOR

Eric Angelini and Giorgos Kalogeropoulos, Feb 17 2024

STATUS

approved