A128264 Triangle read by rows, 1 <= m <= n: t(n,m) = 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.

1, 1, 1, 2, 3, 1, 6, 77, 6, 1, 24, 150, 175, 10, 1, 120, 8494, 450, 1105, 15, 1, 720, 1764, 69832, 7350, 700, 21, 1, 5040, 1659636, 906108, 1644867, 29400, 6118, 28, 1, 40320, 9314640, 357325100, 12447540, 7430619, 31752, 6006, 36, 1, 362880, 524580336

Offset

1,4

Links

Table of n, a(n) for n=1..47.

Formula

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

Example

Triangle starts
    1;
    1,    1;
    2,    3,     1;
    6,   77,     6,    1;
   24,  150,   175,   10,   1;
  120, 8494,   450, 1105,  15,  1;
  720, 1764, 69832, 7350, 700, 21, 1;

Maple

A128264 := proc(n, m) lcm(combinat[stirling1](n, m), combinat[stirling2](n, m)) ; end: for n from 1 to 10 do for m from 1 to n do printf("%d, ", A128264(n, m)) ; od: od: # R. J. Mathar, Sep 24 2007

Prog

(PARI) tabl(nn) = {for (n=1, nn, for (k=1, n, print1(lcm(stirling(n, k, 1), stirling(n, k, 2)), ", "); ); print(); ); } \\ Michel Marcus, Aug 18 2015

Crossrefs

Cf. A128265.

Cf. A000142 (T(n,1)), A000217 (T(n, n-1)).

Sequence in context: A130850 A130405 A058372 * A232435 A114858 A193491

Adjacent sequences: A128261 A128262 A128263 * A128265 A128266 A128267

Keyword

nonn,tabl

Author

Leroy Quet, Feb 22 2007

Extensions

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

Status

approved