A079882 - OEIS

A079882

A run of 2^n 1's followed by a run of 2^n 2's, for n=0, 1, 2, ...

1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2

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OFFSET

0,2

COMMENTS

In the sequence of nonnegative integers (cf. A001477) substitute all n by 2^floor(n/2) occurrences of (1 + n mod 2); a(n)=A173920(n+2,3) for n>0. [From Reinhard Zumkeller, Mar 04 2010]

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = floor(log[2](8*(n+2)/3)) - floor(log[2](n+2)). - Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Feb 22 2003

MAPLE

f1 := n->[seq(1, i=1..2^n)]; f2 := n->[seq(2, i=1..2^n)]; s := []; for i from 0 to 10 do s := [op(s), op(f1(i)), op(f2(i))]; od: s;

MATHEMATICA

Table[{PadRight[{}, 2^n, 1], PadRight[{}, 2^n, 2]}, {n, 0, 5}]//Flatten (* Harvey P. Dale, Jul 22 2016 *)

CROSSREFS

Partial sums give A079945. Equals 1 + A079944. Cf. A080584.

First differences of A080637.

Sequence in context: A091243 A306615 A037826 * A362415 A317335 A014709