A125153 - OEIS

%I #5 Mar 30 2012 18:57:06

%S 1,4,2,13,6,3,40,20,10,5,121,60,30,15,7,364,182,91,45,22,8,1093,546,

%T 273,136,68,25,9,3280,1640,820,410,205,76,28,11,9841,4920,2460,1230,

%U 615,230,86,34,12,29524,14762,7381,3690,1845,691,259,102,38,14

%N The interspersion T(3,2,1), by antidiagonals.

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

%D 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.

%H C. Kimberling, <a href="http://faculty.evansville.edu/ck6/integer/intersp.html">Interspersions and Dispersions</a>.

%F Row 1: t(1,h)=Floor[r*3^(h-1)], where r=(3^1)/(2^1), 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=(3^3)/(2^3), where 3=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 >=1 for which there is an integer j for which the LPI not in rows 1,2,...,m-1 is Floor[r].

%e Northwest corner:

%e 1 4 13 40 121 364 1093

%e 2 6 20 60 182 546 1640

%e 3 10 30 91 273 820 2460

%e 5 15 45 136 410 1230 3690

%e 7 22 68 205 615 1845 5535

%Y Cf. A125157, A125161.

%K nonn,tabl

%O 1,2

%A _Clark Kimberling_, Nov 21 2006