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A227932 Evil numbers (A001969) which can be written as a product of two odious numbers (A000069). 3
77, 147, 154, 169, 175, 209, 231, 245, 275, 287, 294, 308, 325, 329, 338, 343, 350, 399, 407, 413, 418, 427, 441, 455, 462, 469, 483, 490, 525, 533, 550, 553, 567, 574, 588, 605, 609, 616, 649, 650, 658, 676, 679, 686, 700, 703, 715, 735, 759, 763, 777, 798 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

Evil number 275 = 25*11. Since 25 and 11 are odious, then 275 is in the sequence.

MATHEMATICA

evilQ[n_] := EvenQ[DigitCount[n, 2][[1]]]; odiousQ[n_] := OddQ[DigitCount[n, 2][[1]]]; fQ[n_] := Module[{f, i}, If[PrimeQ[n], False, f = Select[Divisors[n], # > 1 && # <= Sqrt[n] &]; i = 1; While[i <= Length[f] && ! (odiousQ[f[[i]]] && odiousQ[n/f[[i]]]), i++]; i <= Length[f]]]; Select[Range[1000], evilQ[#] && fQ[#] &] (* T. D. Noe, Oct 16 2013 *)

CROSSREFS

Cf. A001969, A000069, A230213, A230226.

Sequence in context: A118611 A072431 A046435 * A004964 A118226 A113945

Adjacent sequences:  A227929 A227930 A227931 * A227933 A227934 A227935

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev, Oct 15 2013

EXTENSIONS

Extended by T. D. Noe, Oct 16 2013

STATUS

approved

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Last modified September 26 20:34 EDT 2021. Contains 347672 sequences. (Running on oeis4.)