

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
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OFFSET

1,2


LINKS

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


EXAMPLE

Let pe(m)=m*(3m1)/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(3m1))/2; While[!Divisible[c, n], m++; c=(m(3m1))/2]; m]; Array[smn, 80] (* Harvey P. Dale, Feb 03 2015 *)


PROG

(PARI) pe(n)=n*(3*n1)/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



