OFFSET

1,3

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

To get the eleventh term, you need to get the last digit of the tenth term, which is 1, and then count all the 1's already in the sequence: 1, 1, 2, 1, 3, 1, 4, 1, 5, 1; there are six 1's, so the eleventh term is 6.

MAPLE

Q:= Array(0..9):

A:= Vector(100):

Q[1]:= 1:

A[1]:= 1:

for n from 2 to 100 do

d:= A[n-1] mod 10;

A[n]:= Q[d];

L:= convert(%, base, 10);

for i in L do Q[i]:= Q[i]+1 od

od:

convert(A, list); # Robert Israel, Feb 18 2020

PROG

(PARI) f = vector(base=10); for (n=1, 91, v = if (n==1, 1, f[1+(v%base)]); apply (d -> f[1+d]++, if (v, digits(v, base), [0])); print1 (v ", ")) \\ Rémy Sigrist, Aug 21 2019

(Python)

s, a, n = "1", [1], 1

while n < 100:

n = n+1

d = s[len(s)-1]

i, aa = 0, 0

while i < len(s):

if s[i] == d:

aa = aa+1

i = i+1

s, a = s+str(aa), a+[aa]

for n in range(1, 92): print(a[n-1], end=', ') # A.H.M. Smeets, Aug 22 2019

CROSSREFS

KEYWORD

AUTHOR

Maxim Skorohodov, Aug 21 2019

STATUS

approved