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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
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: A166007 A372748 A087497 * A082127 A031354 A307486
KEYWORD
nonn
AUTHOR
Jon Perry, Jul 22 2003
EXTENSIONS
More terms from David Wasserman, Feb 10 2005
STATUS
approved

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Last modified May 24 21:23 EDT 2024. Contains 372781 sequences. (Running on oeis4.)