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A065447 Concatenation of 1, 00, 111, 0000, ..., n 1's (if n is odd) or n 0's (if n is even). 5
1, 100, 100111, 1001110000, 100111000011111, 100111000011111000000, 1001110000111110000001111111, 100111000011111000000111111100000000, 100111000011111000000111111100000000111111111, 1001110000111110000001111111000000001111111110000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is divisible by A002275([(n+1)/2]) = (10^[(n+1)/2]-1)/9. Cf. A262806. - Max Alekseyev, Jun 02 2013

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,44

EXAMPLE

a(2) = 100, the concatenation of one 1, two 0s.

a(3) = 100111, the concatenation of one 1, two 0s, three 1s.

a(4) = 1001110000, the concatenation of one 1, two 0s, three 1s, four 0s.

PROG

(PARI) { m=10; for (n=1, 44, if (n==1, a=1, m*=10; a*=m; if (n%2, a+=(m - 1)/9)); write("b065447.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 19 2009

CROSSREFS

For decimal version see A065760. Cf. A065761.

Sequence in context: A307810 A151648 A013747 * A036507 A202055 A185303

Adjacent sequences:  A065444 A065445 A065446 * A065448 A065449 A065450

KEYWORD

base,easy,nonn

AUTHOR

Lior Manor, Nov 18 2001

STATUS

approved

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Last modified November 21 22:35 EST 2019. Contains 329383 sequences. (Running on oeis4.)