login
Number of step cyclic shifted sequences using exactly two different symbols.
2

%I #10 Aug 22 2017 20:53:11

%S 0,1,2,4,4,11,8,22,20,43,28,156,72,243,366,691,520,2635,1608,7384,

%T 8866,19399,16768,94482,67560,216273,277532,815556,662368,4500265,

%U 2311468,8466187,13045106,31593283,40937604,159772174,103197488,401913695

%N Number of step cyclic shifted sequences using exactly two different symbols.

%C See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent.

%D M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

%F a(n) = A002729(n) - 2.

%Y Cf. A002729.

%K nonn

%O 1,3

%A _Marks R. Nester_

%E Added more terms (from A002729), _Joerg Arndt_, Aug 27 2014