A115345 - OEIS

%I #8 Mar 13 2015 22:35:04

%S 1,1,1,2,1,5,2,17,8,10,5,9,29,46,45,29,24,114,126,72,25,55,31,192,45,

%T 341,6,165,62,196,30,330,740,90,4,455,67,356,1549,216,145,996,182,647,

%U 1118,1565,55,610,3141,2729,205,2159,392,1360,1177,2249,1142,766,65,382

%N Position of n^4 in the lexicographically arranged permutations of digits of n^4.

%e a(5)=5 because 5^4=625 and {6, 2, 5} is at 5th position among 6 permutations of {2, 5, 6}: {{2, 5, 6}, {2, 6, 5}, {5, 2, 6}, {5, 6, 2}, {6, 2, 5}, {6, 5, 2}}; a(7)=17 because 7^4=2401 and {2, 4, 0, 1} is at 17th position among 24 permutations of {0, 1, 2, 4}: {{0, 1, 2, 4}, {0, 1, 4, 2}, {0, 2, 1, 4}, {0, 2, 4, 1}, {0, 4, 1, 2}, {0, 4, 2, 1}, {1, 0, 2, 4}, {1, 0, 4, 2}, {1, 2, 0, 4}, {1, 2, 4, 0}, {1, 4, 0, 2}, {1, 4, 2, 0}, {2, 0, 1, 4}, {2, 0, 4, 1}, {2, 1, 0, 4}, {2, 1, 4, 0}, {2, 4, 0, 1}, {2, 4, 1, 0}, {4, 0, 1, 2}, {4, 0, 2, 1}, {4, 1, 0, 2}, {4, 1, 2, 0}, {4, 2, 0, 1}, {4, 2, 1, 0}}.

%t Reap[Do[per=Permutations[Sort[tn=IntegerDigits[n^4]]];Sow[Position[per,tn]],{n,0,100}]]

%K nonn,base

%O 0,4

%A _Zak Seidov_, Apr 02 2006