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A280062 a(n) = A049502(A000142(n)).

%I A280062 #25 Jan 04 2017 14:11:48
%S A280062 0,0,0,0,0,0,13,16,22,38,47,73,60,127,160,166,194,249,348,345,359,497,
%T A280062 532,682,709,727,1000,887,1312,1155,1297,1934,2069,1722,1796,2148,
%U A280062 2337,1839,2595,2774,2440,3314,3450,3253,3379,3786,4466,4366,4795,5189,5598
%N A280062 a(n) = A049502(A000142(n)).
%C A280062 a(n) is the major index (2nd definition) of n!.
%H A280062 Indranil Ghosh, <a href="/A280062/b280062.txt">Table of n, a(n) for n = 0..10000</a>
%e A280062 for n=15, A000142(n) = 1307674368000 and A049502(1307674368000) = 166. So a(n) = 166.
%o A280062 (Python)
%o A280062 import math
%o A280062 def m(N):
%o A280062     x=bin(int(N))[2:][::-1]
%o A280062     s=0
%o A280062     for i in range(1,len(x)):
%o A280062         if x[i-1]=="1" and x[i]=="0":
%o A280062             s+=i
%o A280062     return s
%o A280062 a=lambda n: m(math.factorial(n))
%Y A280062 Cf. A049502, A000142.
%K A280062 nonn
%O A280062 0,7
%A A280062 _Indranil Ghosh_, Jan 04 2017