login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071145 Numbers n such that sum of distinct primes dividing n is divisible by the largest prime dividing n. Also n has exactly 6 distinct prime factors and n is squarefree. 0
72930, 106590, 190190, 222870, 335478, 397670, 620310, 836418, 844305, 884442, 1008678, 1195670, 1218945, 1247290, 1704794, 1761110, 1799798, 2086238, 2206022, 2328410, 2485830, 2496585, 2517258, 2863718, 2903538, 3024021 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

A008472(n)/A006530(n) is integer; A001221(n)=6, n is squarefree.

EXAMPLE

n=pqrstw, p<q<r<s<t<w, primes, p+q+r+s+t+w=kt; n=106590=2.3.5.11.17.19; sum=2+3+5+11+17+19=57=3.19 (quotient=3) (Corrected Mar 06 2006.)

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], 6]&& !Equal[amo[n], 0], Print[{n, ba[n]}]], {n, 2, 1000000}]

CROSSREFS

Cf. A008472, A006530, A000961, A025475, A037074, A071139-A071147.

Sequence in context: A114258 A186047 A161730 * A023185 A184769 A105648

Adjacent sequences:  A071142 A071143 A071144 * A071146 A071147 A071148

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), May 13 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 19:13 EST 2012. Contains 206085 sequences.