A077193 - OEIS

%I #24 Oct 07 2023 21:38:53

%S 1,1,6,6,24,360,720,5040,362880,1814400,23587200,1089728640

%N Number of multiples of n that can be obtained by permuting the digits of number formed by the concatenation of first n numbers.

%e a(4) = 6 as using the digits of 1234 one gets six multiples of 4 e.g. 1324,3124,1432,4132,4312 and 3412.

%o (PARI) a(n)={my(X=vecsort(concat(vector(n,i,digits(i)))), s=0); forperm(X, p, if(fromdigits(Vec(p))%n==0, s+=1)); s} \\ _Andrew Howroyd_, Oct 07 2023

%K nonn,base,more

%O 1,3

%A _Amarnath Murthy_, Nov 01 2002

%E More terms from _Sascha Kurz_, Jan 04 2003

%E Offset corrected and a(11)-a(12) from _Andrew Howroyd_, Oct 07 2023