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A132068 Irregular array: row n has A000010(n) terms: the sum of the first m terms of row n is the m-th positive integer which is coprime to n. 0
1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 2, 1, 2, 1, 1, 2, 4, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 2, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 4, 2, 2, 1, 1, 2, 3, 1, 3, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 2, 4, 2, 4, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

The first term of each row is 1. The sum of the terms of row n is n-1, for n>=2. After the initial 1, the remaining terms of each row are the same forward or backward.

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

The positive integers which are <= 12 and are coprime to 12 are 1,5,7,11. Row 12 of the array is: 1,4,2,4. So we have: 1=1; 1+4=5; 1+4+2=7; 1+4+2+4=11.

The first 12 rows of the array:

1;

1;

1,1;

1,2;

1,1,1,1;

1,4;

1,1,1,1,1,1;

1,2,2,2;

1,1,2,1,2,1;

1,2,4,2;

1,1,1,1,1,1,1,1,1,1;

1,4,2,4

MATHEMATICA

f[n_] := Block[{g}, g = Select[Range[n], GCD[ #, n] == 1 &]; g - Prepend[Most[g], 0]]; Flatten[Array[f, 25]] (* Ray Chandler, Nov 01 2007 *)

CROSSREFS

Cf. A038566, A000010.

Sequence in context: A247487 A010248 A325403 * A173441 A326851 A129192

Adjacent sequences:  A132065 A132066 A132067 * A132069 A132070 A132071

KEYWORD

nonn,tabf

AUTHOR

Leroy Quet, Oct 30 2007

EXTENSIONS

Extended by Ray Chandler, Nov 01 2007

STATUS

approved

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Last modified December 11 07:35 EST 2019. Contains 329914 sequences. (Running on oeis4.)