A086846 -id:A086846 - cp's OEIS frontend

A087434 Number of brilliant numbers whose prime factors each have n digits.

10, 231, 10296, 563391, 34974066, 2374052871, 171745762321, 12989075028126, 1016377282340160, 81690831917887753, 6708792934060150753, 560785267822390134615, 47573053155260626453431

Offset: 1

Ray Chandler, Sep 02 2003

Number of brilliant numbers having 2n or 2n-1 digits.

Charles R Greathouse IV, Table of n, a(n) for n = 1..24

Cf. A006879, A006880, A078972, A086846, A087435.

a(n)=binomial(primepi(10^n)-primepi(10^(n-1))+1,2)
\\ Charles R Greathouse IV, May 03 2012

a(n)=A000217(A006879(n)).

a(14) from Ray Chandler, Jul 21 2005

A087435 Partial sums of A087434.

Original entry on oeis.org

10, 241, 10537, 573928, 35547994, 2409600865, 174155363186, 13163230391312, 1029540512731472, 82720372430619225, 6791513306490769978, 567576781128880904593, 48140629936389507358024

Offset: 1

Ray Chandler, Sep 02 2003

nonn

Number of brilliant numbers <10^2n.

Bisection of A086846.

Cf. A006879, A006880, A078972, A086846, A087434.

a(14) from Ray Chandler, Jul 21 2005

cp's OEIS Frontend

A087434 Number of brilliant numbers whose prime factors each have n digits.

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