login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139246 Triangle read by rows: row n lists the proper divisors of n-th perfect number A000396(n). 1
1, 2, 3, 1, 2, 4, 7, 14, 1, 2, 4, 8, 16, 31, 62, 124, 248, 1, 2, 4, 8, 16, 32, 64, 127, 254, 508, 1016, 2032, 4064, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8191, 16382, 32764, 65528, 131056, 262112, 524224, 1048448, 2096896, 4193792, 8387584, 16775168, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Rows n has A133033(n) terms.

The n-th row sum is the n-th perfect number A000396(n).

LINKS

Table of n, a(n) for n=1..56.

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

EXAMPLE

Triangle begins:

1, 2, 3

1, 2, 4, 7, 14

1, 2, 4, 8, 16, 31, 62, 124, 248

CROSSREFS

Cf. A000396, A018254, A018487, A133024, A133025, A133031, A133033, A135652, A135653, A135654, A135655, A139247.

Sequence in context: A081536 A297497 A152736 * A187247 A131227 A190257

Adjacent sequences:  A139243 A139244 A139245 * A139247 A139248 A139249

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Apr 22 2008, corrected Apr 25 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 27 06:18 EST 2022. Contains 350601 sequences. (Running on oeis4.)