Number of different ways n! can be represented as the difference of two squares; also, for n >= 4, half the number of positive integer divisors of n!/4.

A138196

Number of different ways n! can be represented as the difference of two squares; also, for n >= 4, half the number of positive integer divisors of n!/4.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =2a(4) =4a(5) =9a(6) =18a(7) =36a(8) =60a(9) =105a(10) =210a(11) =324a(12) =648a(13) =1080a(14) =1680a(15) =2352a(16) =4704a(17) =6480a(18) =12960a(19) =18360a(20) =27200a(21) =43200a(22) =86400a(23) =110880a(24) =155232a(25) =243936a(26) =310464a(27) =423360a(28) =846720a(29) =1080000

External references