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A036556
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Integers which when multiplied by 3 have an odd number of 1's in their binary expansion (cf. A000069).
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2
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7, 14, 23, 27, 28, 29, 31, 39, 46, 54, 56, 57, 58, 62, 71, 78, 87, 91, 92, 93, 95, 103, 107, 108, 109, 111, 112, 113, 114, 115, 116, 117, 119, 123, 124, 125, 127, 135, 142, 151, 155, 156, 157, 159, 167, 174, 182, 184, 185, 186, 190, 199, 206, 214
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| In other words, numbers n such that 3n is odious.
Numbers n such that valuation(binomial(3n,n),2) is odd. - Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 06 2004
Intersection of A000069 and A008585 (multiples of 3), divided by 3.
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MATHEMATICA
| Select[ Range[ 214 ], OddQ[ Plus@@IntegerDigits[ 3#, 2 ]]& ]
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PROG
| (PARI) for(n=1, 214, if(valuation(binomial(3*n, n), 2)%2==1, print1(n, ", ")))
(MAGMA) [ n : n in [0..150] | IsOdd(&+Intseq(3*n, 2))]; // Vincenzo Librandi, Apr 13 2011
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CROSSREFS
| Cf. A000069, A036555-A036557.
Sequence in context: A018890 A118502 A190367 * A013644 A178894 A050953
Adjacent sequences: A036553 A036554 A036555 * A036557 A036558 A036559
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KEYWORD
| nonn,base
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AUTHOR
| Dan Hoey (Hoey(AT)AIC.NRL.Navy.Mil)
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EXTENSIONS
| Definition corrected Jan 09 2007
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