a(n) = Sum_{m=1..n} gcd(s(n,m), S(n,m)), where s(n,m) is an unsigned Stirling number of the first kind and S(n,m) is a Stirling number of the second kind.

A128266

a(n) = Sum_{m=1..n} gcd(s(n,m), S(n,m)), where s(n,m) is an unsigned Stirling number of the first kind and S(n,m) is a Stirling number of the second kind.

Terms

    a(0) =1a(1) =2a(2) =5a(3) =9a(4) =22a(5) =68a(6) =163a(7) =136a(8) =525a(9) =14519a(10) =3918a(11) =5954a(12) =26561a(13) =23897a(14) =875479a(15) =464545a(16) =303146a(17) =1576515a(18) =15328385a(19) =1297494a(20) =25992621a(21) =92698823a(22) =64096034a(23) =31484634a(24) =16667307085a(25) =737157766a(26) =397339059223a(27) =115011291216a(28) =30816653208a(29) =4304179162

External references