The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A000051 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A000051

a(n) = 2^n + 1.
(history; published version)

#241 by Joerg Arndt at Wed Feb 07 01:12:49 EST 2024

STATUS

editing

approved

#240 by Paolo P. Lava at Tue Feb 06 07:26:17 EST 2024

COMMENTS

Numbers n for which the expression 2^n/(n-1) is an integer. - Paolo P. Lava, May 12 2006

STATUS

approved

editing

#239 by Alois P. Heinz at Mon Nov 06 10:30:29 EST 2023

STATUS

editing

approved

#238 by Alois P. Heinz at Mon Nov 06 10:30:25 EST 2023

DATA

2, 3, 5, 9, 17, 33, 65, 129, 257, 513, 1025, 2049, 4097, 8193, 16385, 32769, 65537, 131073, 262145, 524289, 1048577, 2097153, 4194305, 8388609, 16777217, 33554433, 67108865, 134217729, 268435457, 536870913, 1073741825, 2147483649, 4294967297, 8589934593

STATUS

approved

editing

#237 by Alois P. Heinz at Mon Nov 06 10:29:07 EST 2023

COMMENTS

Letting a(n+1) = k*a(n) - 1; x = (a(n)/a(n+1))^a(n); y = (a(n)/a(n+1))^a(n+1) then x^y = y^(x^k) => this case k=2: x^y = y^(x^2). - Andrea Pinos, Nov 06 2023

KEYWORD

nonn,easy,changed

STATUS

editing

approved

#236 by Alois P. Heinz at Mon Nov 06 10:26:09 EST 2023

STATUS

proposed

editing

Discussion

Mon Nov 06

10:27

Alois P. Heinz: citing Joerg Arndt from the history: "to me this is just noise that does not belong here" ...

10:27

Joerg Arndt: not convinced either...

10:28

Alois P. Heinz: ... reverting ...

#235 by Andrea Pinos at Mon Nov 06 09:26:09 EST 2023

STATUS

editing

proposed

Discussion

Mon Nov 06

09:54

Michel Marcus: not really convinced

10:26

Alois P. Heinz: no ...

#234 by Andrea Pinos at Mon Nov 06 09:26:03 EST 2023

COMMENTS

Letting a(n+1) = k*a(n) - 1; x = (a(n)/a(n+1))^a(n); y = (a(n)/a(n+1))^a(n+1) then x^y = y^(x^k) => this case k=2: x^y = y^(x^2). - Andrea Pinos, Nov 06 2023

STATUS

approved

editing

#233 by N. J. A. Sloane at Wed Dec 21 20:12:49 EST 2022

STATUS

proposed

approved

#232 by Chai Wah Wu at Wed Dec 21 18:24:01 EST 2022

STATUS

editing

proposed