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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038110 (Numerator of) frequency of integers with smallest divisor Prime[ n ]. 7
1, 1, 1, 4, 8, 16, 192, 3072, 55296, 110592, 442368, 13271040, 477757440, 19110297600, 802632499200, 1605264998400, 6421059993600, 12842119987200, 770527199232000, 50854795149312000, 3559835660451840000 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

LINKS

F. Ellermann, Illustration for A002110, A005867, A038110, A060753

Eric Weisstein's World of Mathematics, Euler Product

FORMULA

a(n) = A005867(n) / gcd( A005867(n), A002110(n) ).

EXAMPLE

a(10) = 110592 = ( 1*2*4*6*10*12*16*18*22 ) / ( 2*3*5*11 )

MATHEMATICA

Numerator@Table[ Product[ 1-1/Prime[ k ], {k, n-1} ]/Prime[ n ], {n, 1, 64} ]

CROSSREFS

Cf. A038111, A002110, A005867, A060753.

Sequence in context: A102358 A038238 A023376 * A130436 A090804 A074025

Adjacent sequences:  A038107 A038108 A038109 * A038111 A038112 A038113

KEYWORD

nonn,frac

AUTHOR

Wouter Meeussen (wouter.meeussen(AT)pandora.be)

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 15 15:20 EST 2012. Contains 205823 sequences.