|
| |
|
|
A071146
|
|
Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n has exactly 7 distinct prime factors and n is squarefree.
|
|
1
| |
|
|
1231230, 2062830, 2181270, 3327870, 3594990, 4224990, 4320030, 4671030, 5162430, 5411406, 5414430, 6767670, 7052430, 7432230, 7870830, 7947030, 8150142, 8273265, 8287230, 8569470, 8804334, 9378390
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
FORMULA
| A008472(n)/A006530(n) is integer; A001221(n)=7, n is squarefree.
|
|
|
EXAMPLE
| n=pqrstu, p<q<r<s<t<u, primes, p+q+r+s+t+u=ku; n=9378390=2.3.5.7.17.37.71; sum=2+3+5+7+17+37+71=142=2.71
|
|
|
MATHEMATICA
| ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] sb[x_] := Apply[Plus, ba[x]] ma[x_] := Part[Reverse[Flatten[FactorInteger[x]]], 2] amo[x_] := Abs[MoebiusMu[x]] Do[s=sb[n]/ma[n]; If[IntegerQ[s]&&Equal[lf[n], 7]&& !Equal[amo[n], 0], Print[{n, ba[n]}]], {n, 2, 1000000}]
|
|
|
CROSSREFS
| Cf. A008472, A006530, A000961, A025475, A037074, A071139-A071147.
Sequence in context: A203259 A192219 A129347 * A178477 A144694 A156113
Adjacent sequences: A071143 A071144 A071145 * A071147 A071148 A071149
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Labos E. (labos(AT)ana.sote.hu), May 13 2002
|
| |
|
|
