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A087434
Number of brilliant numbers whose prime factors each have n digits.
3
10, 231, 10296, 563391, 34974066, 2374052871, 171745762321, 12989075028126, 1016377282340160, 81690831917887753, 6708792934060150753, 560785267822390134615, 47573053155260626453431
OFFSET
1,1
COMMENTS
Number of brilliant numbers having 2n or 2n-1 digits.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..24
FORMULA
a(n)=A000217(A006879(n)).
PROG
(PARI) a(n)=binomial(primepi(10^n)-primepi(10^(n-1))+1, 2)
\\ Charles R Greathouse IV, May 03 2012
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ray Chandler, Sep 02 2003
EXTENSIONS
a(14) from Ray Chandler, Jul 21 2005
STATUS
approved