The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A044972 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A044972

Numbers whose base-3 representation contains exactly one 0 and two 1's.
(history; published version)

#23 by Joerg Arndt at Wed Jul 26 03:20:56 EDT 2023

STATUS

proposed

approved

#22 by Jon E. Schoenfield at Wed Jul 26 01:27:19 EDT 2023

STATUS

editing

proposed

#21 by Jon E. Schoenfield at Wed Jul 26 01:27:10 EDT 2023

NAME

Numbers n with property that in whose base-3 representation the numbers of contains exactly one 0's and two 1's are 1 and 2, respectively.

CROSSREFS

Cf. A007089, A024023.

STATUS

approved

editing

#20 by Michel Marcus at Tue Aug 20 02:37:57 EDT 2019

STATUS

reviewed

approved

#19 by Joerg Arndt at Tue Aug 20 02:22:27 EDT 2019

STATUS

proposed

reviewed

#18 by Joerg Arndt at Tue Aug 20 02:22:24 EDT 2019

STATUS

editing

proposed

#17 by Joerg Arndt at Tue Aug 20 02:22:19 EDT 2019

PROG

(Python)

def inA044972(n):

aa = [0, 0, 0]

while n != 0:

aa[n%3], n = aa[n%3]+1, n//3

return aa[0] == 1 and aa[1] == 2

n, a = 1, 0

while n < 20:

if inA044972(a):

print(n, a)

n = n+1

a = a+1 # A.H.M. Smeets, Aug 19 2019

STATUS

proposed

editing

#16 by Jon E. Schoenfield at Mon Aug 19 23:29:11 EDT 2019

STATUS

editing

proposed

Discussion

Tue Aug 20

01:21

Michel Marcus: the python program output is for a bfile? should it not rather be for data section ?

#15 by Jon E. Schoenfield at Mon Aug 19 23:29:08 EDT 2019

NAME

Numbers n with property that in base -3 representation the numbers of 0's and 1's are 1 and 2, respectively.

STATUS

proposed

editing

#14 by A.H.M. Smeets at Mon Aug 19 19:37:19 EDT 2019

STATUS

editing

proposed