A128265 a(n) = Sum_{m=1..n} lcm(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. (a(n) = sum of terms in n-th row of triangle A128264.)

1, 2, 6, 90, 360, 10185, 80388, 4251198, 386596014, 5895746318, 42232772098, 7792102093721, 89950696066660, 1573136478232189, 948484950999782040, 892212203897135193546, 18041218934546986331084

Offset

1,2

Links

Table of n, a(n) for n=1..17.

Formula

T(n,m) = lcm(A008277(n,m), |A008275(n,m)|). - R. J. Mathar, Sep 24 2007

Maple

A128264 := proc(n, m) lcm(combinat[stirling1](n, m), combinat[stirling2](n, m)) ; end: A128265 := proc(n) local m; add( A128264(n, m), m=1..n) ; end: seq(A128265(n), n=1..30) ; # R. J. Mathar, Sep 24 2007

Crossrefs

Cf. A128264.

Sequence in context: A334779 A305598 A179214 * A002432 A087277 A177861

Adjacent sequences: A128262 A128263 A128264 * A128266 A128267 A128268

Keyword

nonn

Author

Leroy Quet, Feb 22 2007

Extensions

More terms from R. J. Mathar, Sep 24 2007

Status

approved