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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139248 Triangle read by rows: row n lists the proper divisors of n-th even superperfect number A061652(n). 1
1, 1, 2, 1, 2, 4, 8, 1, 2, 4, 8, 16, 32, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 1, 2, 4, 8, 16 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Also, row n list the proper divisors of n-th superperfect number A019279(n), if there are no odd superperfect numbers.

Row n has (A000043(n) - 1) = A090748(n)) terms.

LINKS

Table of n, a(n) for n=1..64.

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos".

EXAMPLE

Triangle begins:

1

1, 2

1, 2, 4, 8

1, 2, 4, 8, 16, 32

1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048

CROSSREFS

Cf. A000043, A000668, A018254, A018487, A019279, A061652, A090748, A133024, A133025, A133031, A133049, A135652, A135653, A135654, A135655, A139246.

Sequence in context: A136102 A279586 A275762 * A138380 A016013 A193384

Adjacent sequences:  A139245 A139246 A139247 * A139249 A139250 A139251

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Apr 22 2008

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 February 21 19:50 EST 2018. Contains 299423 sequences. (Running on oeis4.)