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!)
A085767 Smallest m such that n divides the pentagonal number A000326(m). 1
1, 3, 3, 3, 2, 3, 5, 11, 9, 7, 4, 3, 9, 7, 12, 11, 6, 27, 13, 27, 12, 4, 8, 27, 17, 35, 27, 19, 10, 12, 21, 43, 15, 23, 5, 27, 25, 19, 9, 27, 14, 12, 29, 11, 27, 8, 16, 75, 33, 67, 6, 35, 18, 27, 15, 75, 51, 39, 20, 27, 41, 31, 54, 43, 22, 15, 45, 40, 54, 7, 24, 27, 49, 99, 42, 19, 26, 39 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

Let pe(m)=m*(3m-1)/2. The pe(1)=1, pe(2)=5, pe(3)=12. As pe(3) is the first divisible by 6, a(6)=3.

MATHEMATICA

smn[n_]:=Module[{m=1, c}, c=(m(3m-1))/2; While[!Divisible[c, n], m++; c=(m(3m-1))/2]; m]; Array[smn, 80] (* Harvey P. Dale, Feb 03 2015 *)

PROG

(PARI) pe(n)=n*(3*n-1)/2 for (n=1, 50, c=1; while (pe(c)%n!=0, c++); print1(c", "))

CROSSREFS

Cf. A011772 (triangular numbers), A019554 (squares).

Sequence in context: A306996 A166007 A087497 * A082127 A031354 A307486

Adjacent sequences: A085764 A085765 A085766 * A085768 A085769 A085770

KEYWORD

nonn

AUTHOR

Jon Perry, Jul 22 2003

EXTENSIONS

More terms from David Wasserman, Feb 10 2005

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 February 2 05:15 EST 2023. Contains 359997 sequences. (Running on oeis4.)