1,2

Every positive integer occurs exactly once and each pair of rows are interspersed after initial terms.

Clark Kimberling, Interspersions and fractal sequences associated with fractions (c^j)/(d^k), Journal of Integer Sequences 10 (2007, Article 07.5.1) 1-8.

C. Kimberling, Interspersions and Dispersions.

Row 1: t(1,h)=Floor[r*3^(h-1)], where r=(3^0)/(2^0), h=1,2,3,... Row 2: t(2,h)=Floor[r*3^(h-1)], r=(3^2)/(2^2), where 2=Floor[r] is least positive integer (LPI) not in row 1. Row 3: t(3,h)=Floor[r*3^(h-1)], r=(3^2)/(2^1), where 4=Floor[r] is the LPI not in rows 1 and 2. Row m: t(m,h)=Floor[r*3^(h-1)], where r=(3^j)/(2^k), where k is the least integer >=0 for which there is an integer j for which the LPI not in rows 1,2,...,m-1 is Floor[r].

Northwest corner:

1 3 9 27 81 243 729

2 6 20 60 182 546 1640

4 13 40 121 364 1093 3280

5 15 45 136 410 1230 3690

7 22 68 205 615 1845 5535

Cf. A125156, A125160.

Sequence in context: A235539 A191449 A175840 * A229119 A269867 A244319

Adjacent sequences: A125149 A125150 A125151 * A125153 A125154 A125155

nonn,tabl

Clark Kimberling, Nov 21 2006, corrected Nov 24 2006

approved