

A184337


a(n) is the integer whose decimal representation consists of n 8's followed by n 1's.


2



0, 81, 8811, 888111, 88881111, 8888811111, 888888111111, 88888881111111, 8888888811111111, 888888888111111111, 88888888881111111111, 8888888888811111111111, 888888888888111111111111, 88888888888881111111111111
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OFFSET

0,2


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200
Richard Blecksmith and Charles Nicol, Monotonic Numbers, Mathematics Magazine, 66, (1993), 257262.
Index entries for linear recurrences with constant coefficients, signature (111,1110,1000).


FORMULA

a(n) = (8*100^n  7*10^n  1)/9.
a(n) = A059482(n)*A002283(n).
G.f.: 9*x*(9+20*x) / ( (x1)*(100*x1)*(10*x1) ).  R. J. Mathar, Feb 28 2011


MATHEMATICA

Table[(8*100^n  7*10^n  1)/9, {n, 0, 30}] (* G. C. Greubel, Nov 02 2018 *)


PROG

(Magma) [(8*100^n7*10^n1)/9: n in [0..20]]; // Vincenzo Librandi, Aug 04 2011
(PARI) vector(30, n, n; (8*100^n  7*10^n  1)/9) \\ G. C. Greubel, Nov 02 2018
(Python)
for n in range(30):
print((8*100**n7*10**n1)//9, end=', ')
# Stefano Spezia, Nov 02 2018


CROSSREFS

Cf. A098210 (with 1 and 5 instead of 8 and 1).
Cf. A002283, A059482.
Cf. A008591 (digits sums).
Sequence in context: A328089 A186527 A178511 * A034993 A223328 A093281
Adjacent sequences: A184334 A184335 A184336 * A184338 A184339 A184340


KEYWORD

nonn,easy,base


AUTHOR

Paul Curtz, Feb 13 2011


STATUS

approved



