A280531 a(n) = A049501(A000142(n)).

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

Indranil Ghosh, Table of n, a(n) for n = 0..10000

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. A000142, A049501.

Cf. A280062 (Major index (2nd definition) of n!).

Sequence in context: A220786 A280673 A363385 * A072074 A052338 A153950

Adjacent sequences: A280528 A280529 A280530 * A280532 A280533 A280534

Keyword

nonn

Author

Indranil Ghosh, Jan 04 2017

Status

approved