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A366585
Write down the positive integers. To obtain the terms of the sequence, concatenate groups of these so the first digit of each term is the number of consecutive numbers that are concatenated.
1
1, 23, 4567, 89101112131415, 16, 17, 18, 19, 2021, 2223, 2425, 2627, 2829, 303132, 333435, 363738, 394041, 42434445, 46474849, 5051525354, 5556575859, 606162636465, 666768697071, 72737475767778, 79808182838485, 8687888990919293, 949596979899100101102, 103, 104, 105, 106, 107
OFFSET
1,2
COMMENTS
Terms beginning with 1 will appear in runs of long linear succession. These are interspersed with clusters of values that tend to increase at other, uneven rates in the sequence.
PROG
(PARI) lista(nn) = my(list=List(), k=1); while (k < nn, my(s="", n=digits(k)[1]); for (j=1, n, s = concat(s, Str(k+j-1)); ); listput(list, eval(s)); k += n; ); Vec(list); \\ Michel Marcus, Oct 14 2023
(Python)
from itertools import islice
def A366585_gen(): # generator of terms
a = 1
while True:
c = a+int(str(a)[0])
yield int(''.join(str(i) for i in range(a, c)))
a = c
A366585_list = list(islice(A366585_gen(), 20)) # Chai Wah Wu, Nov 04 2023
CROSSREFS
Sequence in context: A059000 A233235 A286706 * A134801 A059932 A045735
KEYWORD
nonn,base
AUTHOR
Tamas Sandor Nagy, Oct 14 2023
STATUS
approved