login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076302 Triangle T(n,k) = number of k-smooth divisors of n, read by rows. 0

%I

%S 1,1,2,1,1,2,1,3,3,3,1,1,1,1,2,1,2,4,4,4,4,1,1,1,1,1,1,2,1,4,4,4,4,4,

%T 4,4,1,1,3,3,3,3,3,3,3,1,2,2,2,4,4,4,4,4,4,1,1,1,1,1,1,1,1,1,1,2,1,3,

%U 6,6,6,6,6,6,6,6,6,6,1,1,1,1,1,1,1,1,1,1,1,1,2,1,2,2,2,2,2,4,4,4,4,4,4,4,4

%N Triangle T(n,k) = number of k-smooth divisors of n, read by rows.

%C T(n,n)=A000005(n);

%C T(n,2)=A001511(n) for n>1; T(n,3)=A072078(n) for n>2.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/DivisorFunction.html">Divisor Function</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SmoothNumber.html">Smooth Number</a>.

%e Triangle begins:

%e .................. 1

%e ................ 1...2

%e .............. 1...1...2

%e ............ 1...3...3...3

%e .......... 1...1...1...1...2

%e ........ 1...2...4...4...4...4

%e ...... 1...1...1...1...1...1...2

%e .... 1...4...4...4...4...4...4...4

%e .. 1...1...3...3...3...3...3...3...3.

%K nonn,tabl

%O 1,3

%A _Reinhard Zumkeller_, Mar 14 2003

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 February 22 17:14 EST 2020. Contains 332140 sequences. (Running on oeis4.)