login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A037095 "Sloping binary representation" of powers of 3 (A000244), slope = -1. 5
1, 1, 3, 1, 3, 9, 11, 17, 19, 25, 123, 65, 195, 169, 171, 753, 435, 249, 2267, 4065, 8163, 841, 843, 31313, 29651 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..24.

FORMULA

a(n) := Sum(bit_n(A000244(n-i), i)*(2^i), i=0..(n-1)) [ bit_n := (x, n) -> `mod`(floor(x/(2^n)), 2); ]

EXAMPLE

When powers of 3 are written in binary (see A004656), under each other as:

000000000001 (1)

000000000011 (3)

000000001001 (9)

000000011011 (27)

000001010001 (81)

000011110011 (243)

001011011001 (729)

100010001011 (2187)

and one collects their bits from the column-0 to NW-direction (from the least to the most significant end), one gets 1 (1), 01 (1), 011 (3), 0001 (1), 00011 (3), 001001 (9), etc. (See A105033 for similar transformation done on nonnegative integers).

CROSSREFS

Cf. A105033, A000244, A037093-A037094, A037096-A037097.

Sequence in context: A265307 A133579 A088442 * A160654 A146436 A058842

Adjacent sequences:  A037092 A037093 A037094 * A037096 A037097 A037098

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Jan 28 1999. Entry revised Dec 29 2007.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 17 04:09 EST 2017. Contains 296096 sequences.