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 A019991 A threequence, a 3-way partitioning of the integers: define a,b,c,A,B,C by a(0)=true, b(0)=c(0)=A(0)=B(0)=C(0)=false, a(n)=a(m) OR C(m) OR B(m), b(n)= b(m) OR A(m) OR C(m), c(n)= c(m) OR B(m) OR A(m), A(n)= A(m) OR b(m) OR c(m), B(n)= B(m) OR c(m) OR a(m), C(n)= C(m) OR a(m) OR b(m), where m = [ (n+1)/3 ]; sequence gives n such that c(2n) is true. 2
 10, 17, 28, 30, 31, 37, 44, 50, 51, 53, 64, 71, 82, 84, 85, 88, 90, 92, 93, 94, 100, 109, 111, 112, 118, 125, 131, 132, 134, 143, 149, 150, 151, 153, 155, 158, 159, 161, 172, 179 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS CROSSREFS Cf. A019989, A019990. Sequence in context: A190771 A034097 A034107 * A164285 A268183 A069546 Adjacent sequences:  A019988 A019989 A019990 * A019992 A019993 A019994 KEYWORD nonn AUTHOR STATUS approved

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