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Search: id:A132068
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| A132068 |
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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. |
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+0
1
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| 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; listen)
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OFFSET
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1,6
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COMMENT
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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.
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EXAMPLE
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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
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MATHEMATICA
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f[n_] := Block[{g}, g = Select[Range[n], GCD[ #, n] == 1 &]; g - Prepend[Most[g], 0]]; Flatten[Array[f, 25]] (*Chandler*)
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CROSSREFS
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Cf. A038566, A000010.
Sequence in context: A070084 A060176 A010248 this_sequence A129192 A062540 A115878
Adjacent sequences: A132065 A132066 A132067 this_sequence A132069 A132070 A132071
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KEYWORD
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nonn,tabf
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AUTHOR
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Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Oct 30 2007
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EXTENSIONS
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Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 01 2007
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