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!)
A074139 Number of divisors of A036035(n,k). 19
1, 2, 3, 4, 4, 6, 8, 5, 8, 9, 12, 16, 6, 10, 12, 16, 18, 24, 32, 7, 12, 15, 16, 20, 24, 27, 32, 36, 48, 64, 8, 14, 18, 20, 24, 30, 32, 36, 40, 48, 54, 64, 72, 96, 128, 9, 16, 21, 24, 25, 28, 36, 40, 45, 48, 48, 60, 64, 72, 81, 80, 96, 108, 128, 144, 192, 256 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
Byungchul Cha et al., An Investigation on Partitions with Equal Products, arXiv:1811.07451 [math.NT], 2018.
FORMULA
T(n,k) = A000005(A036035(n,k)). - R. J. Mathar, Aug 28 2018
EXAMPLE
Express A036035(n,k) by its prime signature; add one to each exponent, then multiply: 180 = (2^2)*(3^2)*(5^1) therefore the number of divisors is (2+1)*(2+1)*(1+1)= 18
From Michel Marcus, Nov 11 2015: (Start)
As an irregular triangle, whose n-th row has A000041(n) terms, sequence begins:
1;
2;
3, 4;
4, 6, 8;
5, 8, 9, 12, 16;
6, 10, 12, 16, 18, 24, 32;
...
(End)
PROG
(PARI) tabf(nn) = {for (n=1, nn, forpart(p=n, print1(prod(k=1, #p, (1+p[k])), ", ")); print(); ); } \\ Michel Marcus, Nov 11 2015
CROSSREFS
Row sums give A074141.
Sequence in context: A351006 A325682 A241088 * A355026 A238963 A342940
KEYWORD
nonn,look,tabf
AUTHOR
Amarnath Murthy, Aug 28 2002
EXTENSIONS
More terms from Alford Arnold, Sep 17 2002
Term ordering corrected by Alois P. Heinz, Aug 21 2019
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 08:01 EDT 2024. Contains 371265 sequences. (Running on oeis4.)