login
A280531
a(n) = A049501(A000142(n)).
2
0, 0, 1, 2, 2, 4, 11, 16, 16, 25, 30, 64, 39, 83, 111, 139, 139, 165, 205, 242, 283, 320, 336, 474, 440, 395, 637, 655, 886, 842, 1019, 1159, 1159, 1153, 1327, 1366, 1328, 1243, 1487, 1756, 1623, 2362, 2394, 2274, 2487, 2642, 2907, 2843, 3211, 3049, 3736
OFFSET
0,4
COMMENTS
a(n) is the major index (1st definition) of n!.
LINKS
EXAMPLE
For n=4, A000142(n) = 24 and A049501(24) = 2. So a(n) = 2.
PROG
(Python)
import math
def M(n):
x=bin(int(n))[2:]
s=0
for i in range(1, len(x)):
if x[i-1]=="1" and x[i]=="0":
s+=i
return s
a=lambda n: M(math.factorial(n))
CROSSREFS
Cf. A280062 (Major index (2nd definition) of n!).
Sequence in context: A220786 A280673 A363385 * A072074 A052338 A153950
KEYWORD
nonn
AUTHOR
Indranil Ghosh, Jan 04 2017
STATUS
approved