[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Revision History for A376531 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
a(n) = (1/2^n) * Sum_{k=0..n^2} ( binomial(n^2,k) (mod 2^n) ).
(history; published version)
#19 by Alois P. Heinz at Wed Oct 09 12:18:56 EDT 2024
STATUS

proposed

approved

#18 by Chai Wah Wu at Wed Oct 09 12:17:25 EDT 2024
STATUS

editing

proposed

#17 by Chai Wah Wu at Wed Oct 09 12:17:20 EDT 2024
PROG

return c>>n # Chai Wah Wu, Oct 09 2024

#16 by Chai Wah Wu at Wed Oct 09 12:17:10 EDT 2024
PROG

(Python)

def A376531(n):

m, r, c, b, d = (1<<n)-1, n**2, 1, n**2, 1

for k in range(1, r+1):

c += b//d&m

b *= r-k

d *= k+1

return c>>n # Chai Wah Wu, Oct 09 2024

STATUS

approved

editing

#15 by Michael De Vlieger at Mon Oct 07 09:07:30 EDT 2024
STATUS

proposed

approved

#14 by James C. McMahon at Mon Oct 07 03:19:14 EDT 2024
STATUS

editing

proposed

#13 by James C. McMahon at Mon Oct 07 03:18:22 EDT 2024
MATHEMATICA

Table[(1/2^n)*Sum[Mod[Binomial[n^2, k], 2^n], {k, 0, n^2}], {n, 60}] (* James C. McMahon, Oct 07 2024 *)

STATUS

approved

editing

#12 by Paul D. Hanna at Sun Oct 06 11:56:45 EDT 2024
STATUS

editing

approved

#11 by Paul D. Hanna at Sun Oct 06 11:56:37 EDT 2024
EXAMPLE

(1+x)^49 (mod 2^7): [1, 49, 24, 120, 36, 68, 72, 40, 18, 82, 72, 104, 52, 20, 88, 120, 95, 79, 112, 48, 72, 8, 80, 16, 60, 60, 16, 80, 8, 72, 48, 112, 79, 95, 120, 88, 20, 52, 104, 72, 82, 18, 40, 72, 68, 36, 120, 24, 49, 1];

CROSSREFS
STATUS

approved

editing

#10 by OEIS Server at Sun Oct 06 09:13:34 EDT 2024
LINKS

Paul D. Hanna, <a href="/A376531/b376531_1.txt">Table of n, a(n) for n = 1..235</a>