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A153638
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Odiousness of triangular numbers.
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0
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0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| The odiousness of a number is equal to 1 if the number is odious, meaning that it has an odd number of ones in its binary expansion. Otherwise, it is zero.
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EXAMPLE
| a(2) is 0, because the second triangular number is 3, which in binary is 11 and has an even number of ones.
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MATHEMATICA
| od[n_] := Mod[Count[IntegerDigits[n, 2], 1], 2] Table[od[n (n + 1)/2], {n, 0, 128}]
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CROSSREFS
| A000217 Triangular numbers.
Sequence in context: A030213 A132151 A103588 * A122415 A109017 A110161
Adjacent sequences: A153635 A153636 A153637 * A153639 A153640 A153641
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KEYWORD
| nonn
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AUTHOR
| Tanya Khovanova (tanyakh(AT)yahoo.com), Dec 29 2008
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