The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A228436 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A228436

Odd n such that n*d are both odious (A000069) or both evil (A001969) for every divisor d of n.
(history; published version)

#15 by T. D. Noe at Tue Nov 12 15:47:13 EST 2013

STATUS

editing

approved

#14 by T. D. Noe at Tue Nov 12 15:47:05 EST 2013

MATHEMATICA

odiousQ[n_]:=OddQ[DigitCount[n, 2][[1]]]; selQ[n_]:=OddQ[n] && Length[Union[Map[odiousQ, Map[n #&, Divisors[n]]]]] == 1; Select[Range[400], selQ] (* _Peter J. C. Moses_, Nov 10 2013 *)

selQ[n_]:=OddQ[n]&&Length[Union[Map[odiousQ, Map[n #&, Divisors[n]]]]]==1;

Select[Range[400], selQ] (* Peter J. C. Moses, Nov 10 2013 *)

STATUS

proposed

editing

#13 by Vladimir Shevelev at Mon Nov 11 05:56:43 EST 2013

STATUS

editing

proposed

#12 by Vladimir Shevelev at Mon Nov 11 05:56:11 EST 2013

EXTENSIONS

More terms from _Mishel Michel Marcus_

#11 by Vladimir Shevelev at Mon Nov 11 05:54:31 EST 2013

EXTENSIONS

More terms from _Mishel Marcus_

#10 by Peter J. C. Moses at Sun Nov 10 15:09:11 EST 2013

LINKS

Peter J. C. Moses, <a href="/A228436/b228436.txt">Table of n, a(n) for n = 1..5000</a>

MATHEMATICA

odiousQ[n_]:=OddQ[DigitCount[n, 2][[1]]];

selQ[n_]:=OddQ[n]&&Length[Union[Map[odiousQ, Map[n #&, Divisors[n]]]]]==1;

Select[Range[400], selQ] (* Peter J. C. Moses, Nov 10 2013 *)

STATUS

proposed

editing

#9 by Michel Marcus at Sun Nov 10 12:31:41 EST 2013

STATUS

editing

proposed

#8 by Michel Marcus at Sun Nov 10 12:30:45 EST 2013

DATA

1, 3, 7, 11, 15, 19, 31, 41, 53, 59, 63, 67, 79, 83, 91, 97, 103, 105, 117, 127, 131, 141, 157, 167, 173, 179, 181, 185, 193, 217, 219, 223, 227, 229, 237, 239, 251, 255, 269, 271, 277, 281, 283, 291, 293, 303, 307, 311, 313, 317, 337, 347, 351, 359, 377

Discussion

Sun Nov 10

12:31

Michel Marcus: Could someone confirm with Mma or other prog ?

#7 by Michel Marcus at Sun Nov 10 12:29:41 EST 2013

PROG

(PARI) isok(n) = (n % 2) && (!(s = sumdiv(n, d, hammingweight(n*d) % 2)) || (s == numdiv(n))); \\ Michel Marcus, Nov 10 2013

STATUS

proposed

editing

#6 by Vladimir Shevelev at Sun Nov 10 08:03:29 EST 2013

STATUS

editing

proposed