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

 

Logo

Many excellent designs for a new banner were submitted. We will use the best of them in rotation.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A104245 Suppose n=(p1^e1)(p2^e2)... where p1,p2,... are the prime numbers and e1,e2,... are nonnegative integers. Then we can define Pn(x) = e1 + (e2)*x + (e3)*(x^2) + (e4)*(x^3) + ... + (ek)*(x^(k-1)) + ... The sequence is the table T(x,n)=Pn(x) read by antidiagonals. A090883 is the main diagonal of this table. 1
0, 0, 1, 0, 1, 1, 0, 1, 2, 2, 0, 1, 3, 2, 1, 0, 1, 4, 2, 4, 2, 0, 1, 5, 2, 9, 3, 1, 0, 1, 6, 2, 16, 4, 8, 3, 0, 1, 7, 2, 25, 5, 27, 3, 2, 0, 1, 8, 2, 36, 6, 64, 3, 4, 2, 0, 1, 9, 2, 49, 7, 125, 3, 6, 5, 1, 0, 1, 10, 2, 64, 8, 216, 3, 8, 10, 16, 3, 0, 1, 11, 2, 81, 9, 343, 3, 10, 17, 81, 4, 1, 0, 1, 12, 2 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,9

LINKS

Table of n, a(n) for n=0..94.

EXAMPLE

a(13)=3 because 3=(p1^0)(p2^1)(p3^0)..., so P3(x)=x. Hence a(13)=T(3,3)=P3(3)=3

CROSSREFS

Cf. A104244.

Sequence in context: A166387 A000209 A170982 * A185287 A167637 A109754

Adjacent sequences:  A104242 A104243 A104244 * A104246 A104247 A104248

KEYWORD

easy,nonn,tabl

AUTHOR

Olaf Voß, Feb 26 2005

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified April 18 23:10 EDT 2014. Contains 240734 sequences.