A177671 - OEIS

%I #5 Mar 02 2016 10:57:16

%S 1,1,70,34650,63063000,304935162828,3227357965784040,

%T 65712161060921061615

%N Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, down, down, down, down.

%Y Cf. A014608.

%K nonn

%O 0,3

%A _R. H. Hardin_, May 10 2010