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Revision History for A354884 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Numbers whose skew binary representation (A169683) is palindromic.
(history; published version)
#11 by Joerg Arndt at Sun Jun 12 02:57:38 EDT 2022
STATUS

reviewed

approved

#10 by Michel Marcus at Sun Jun 12 02:29:49 EDT 2022
STATUS

proposed

reviewed

#9 by Amiram Eldar at Sun Jun 12 02:04:12 EDT 2022
STATUS

editing

proposed

#8 by Amiram Eldar at Sun Jun 12 01:36:24 EDT 2022
LINKS

Amiram Eldar, <a href="/A354884/b354884.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#7 by Peter Luschny at Sat Jun 11 03:33:04 EDT 2022
STATUS

reviewed

approved

#6 by Joerg Arndt at Sat Jun 11 01:23:57 EDT 2022
STATUS

proposed

reviewed

#5 by Amiram Eldar at Fri Jun 10 03:43:54 EDT 2022
STATUS

editing

proposed

#4 by Amiram Eldar at Fri Jun 10 03:43:41 EDT 2022
CROSSREFS

SubsequenceSubsequences: A000079, A000295, A144414.

#3 by Amiram Eldar at Fri Jun 10 03:42:12 EDT 2022
COMMENTS

A000295 is a subsequence since A169683(A000295(0)) = A169683(A000295(1)) = 0 and for n>1 A169683(A000295(n)) is a repunit with n-1 1's.

#2 by Amiram Eldar at Fri Jun 10 03:29:38 EDT 2022
NAME

allocated for Amiram EldarNumbers whose skew binary representation (A169683) is palindromic.

DATA

0, 1, 2, 4, 8, 11, 16, 26, 32, 39, 50, 57, 64, 86, 98, 120, 128, 143, 166, 181, 194, 209, 232, 247, 256, 302, 326, 372, 386, 432, 456, 502, 512, 543, 590, 621, 646, 677, 724, 755, 770, 801, 848, 879, 904, 935, 982, 1013, 1024, 1118, 1166, 1260, 1286, 1380, 1428

OFFSET

1,3

COMMENTS

The sequence of powers of 2 (A000079) is a subsequence since A169683(1) = 1, A169683(2) = 2, and for n > 2 A169683(2^n) = 10..01 with n-1 0's between the two 1's.

A000295 is a subsequence since A169683(A000295(0)) = A169683(A000295(1)) = 0 and for n>1 A169683(A000295(n))is a repunit with n-1 1's.

A144414 is a subsequence since A169683(A144414(1)) = 1 and for n>1 A169683(A144414(n)) = 1010..01 with n-1 0's interleaved with n 1's.

EXAMPLE

The first 10 terms are:

n a(n) A169683(a(n))

-- ---- -------------

1 0 0

2 1 1

3 2 2

4 4 11

5 8 101

6 11 111

7 16 1001

8 26 1111

9 32 10001

10 39 10101

MATHEMATICA

f[0] = 0; f[n_] := Module[{m = Floor@Log2[n + 1], d = n, pos}, Reap[While[m > 0, pos = 2^m - 1; Sow@Floor[d/pos]; d = Mod[d, pos]; --m; ]][[2, 1]] // FromDigits]; Select[Range[0, 15000], PalindromeQ[f[#]] &] (* after N. J. A. Sloane at A169683 *)

CROSSREFS
KEYWORD

allocated

nonn,base

AUTHOR

Amiram Eldar, Jun 10 2022

STATUS

approved

editing