The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A262963

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

A262963

List of numbers n whose base-3 expansion contains only the digits 1 and 2 and whose base-4 expansion contains only the digits 2 and 3.
(history; published version)

#20 by N. J. A. Sloane at Sat Oct 31 00:35:39 EDT 2015

STATUS

proposed

approved

#19 by Jon E. Schoenfield at Sat Oct 31 00:21:19 EDT 2015

STATUS

editing

proposed

#18 by Jon E. Schoenfield at Sat Oct 31 00:21:17 EDT 2015

NAME

List of numbers n whose base -3 expansion contains only the digits 1 and 2 and whose base -4 expansion contains only the digits 2 and 3.

STATUS

proposed

editing

#17 by Chai Wah Wu at Fri Oct 30 23:38:38 EDT 2015

STATUS

editing

proposed

#16 by Chai Wah Wu at Fri Oct 30 23:38:21 EDT 2015

PROG

n += 1 # Chai Wah Wu, Oct 30 2015

#15 by Chai Wah Wu at Fri Oct 30 23:38:08 EDT 2015

PROG

(Python)

from gmpy2 import digits

def f1(n):

s = digits(n, 3)

m = len(s)

for i in range(m):

if s[i] == '0':

return(int(s[:i]+'1'*(m-i), 3))

return n

def f2(n):

s = digits(n, 4)

m = len(s)

for i in range(m):

if s[i] in ['0', '1']:

return(int(s[:i]+'2'*(m-i), 4))

return n

A262963_list = []

n = 1

for i in range(10**4):

m = f2(f1(n))

while m != n:

n, m = m, f2(f1(m))

A262963_list.append(m)

n += 1 # Chai Wah Wu, Oct 30 2015

#14 by Chai Wah Wu at Fri Oct 30 23:35:41 EDT 2015

LINKS

Chai Wah Wu, <a href="/A262963/b262963.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#13 by N. J. A. Sloane at Thu Oct 29 23:02:09 EDT 2015

STATUS

editing

approved

#12 by N. J. A. Sloane at Thu Oct 29 23:01:42 EDT 2015

NAME

Numbers List of numbers n in whose base b where 3 expansion contains only the number digits 1 and 2 and whose base 4 expansion contains only the two highest digits for both b=3 2 and b=43.

STATUS

proposed

editing

Discussion

Thu Oct 29

23:02

N. J. A. Sloane: I rewrote the definition to make it clearer - hope that's OK

#11 by Robin Powell at Wed Oct 14 06:09:15 EDT 2015

STATUS

editing

proposed

Discussion

Wed Oct 14

06:12

Robin Powell: I've added every term less than 4 mil, just over 260 characters in total.