A064223 a(1) = 1; a(n+1) = a(n) + number of decimal digits of a(n) for n > 0.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 103, 106, 109, 112, 115, 118, 121, 124, 127, 130, 133, 136

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Formula

a(1) = 1; a(n+1) = a(n) + ceiling(log_10(a(n) + 1)) for n > 0. [corrected by Harry J. Smith, Sep 10 2009]

Mathematica

NestList[#+IntegerLength[#]&, 1, 70] (* Harvey P. Dale, Jul 26 2011 *)

Prog

(PARI) { a=0; for (n=1, 1000, write("b064223.txt", n, " ", a+=#Str(a)) ) } \\ Harry J. Smith, Sep 10 2009
(Haskell)
a064223 n = a064223_list !! (n-1)
a064223_list = iterate (\x -> x + (fromIntegral $ a055642 x)) 1
-- Reinhard Zumkeller, Aug 02 2012
(Python)
from itertools import islice
def agen():
    an = 1
    while True: yield an; an += len(str(an))
print(list(islice(agen(), 67))) # Michael S. Branicky, Jul 26 2022

Crossrefs

Cf. A055642.

Sequence in context: A032960 A117804 A088235 * A098952 A144688 A164836

Adjacent sequences: A064220 A064221 A064222 * A064224 A064225 A064226

Keyword

nice,nonn,base

Author

Reinhard Zumkeller, Sep 21 2001

Status

approved