cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A156824 Generalized q-Stirling 2nd numbers (see A022166):q=3;m=2; t1(n, k, q_) = (1/(q - 1)^k)*Sum[(-1)^(k - j)*Binomial[k + n, k -j]*q-Binomial[j + n, j, q - 1], {j, 0, k}].

Original entry on oeis.org

1, 1, 1, 1, 5, 21, 1, 18, 255, 3400, 1, 58, 2575, 106400, 4300541, 1, 179, 24234, 3038714, 371984935, 45182779173, 1, 543, 221886, 83805218, 30877084287, 11284441459641, 4113010719221412, 1, 1636, 2010034, 2280772380, 2523761295627, 2769755537579952, 3031455813294108948, 3314879002466198503080
Offset: 0

Views

Author

Roger L. Bagula, Feb 16 2009

Keywords

Comments

Row sums are: {1, 2, 27, 3674, 4409575, 45557827236, 4124326121792988, 3317913230561074271658, 23891408190421363405102296351, 1544865931069396100350109616919010834, 898255701914264060744770399113246348926078875,...}.

Examples

			{1},
{1, 1},
{1, 5, 21},
{1, 18, 255, 3400},
{1, 58, 2575, 106400, 4300541},
{1, 179, 24234, 3038714, 371984935, 45182779173},
{1, 543, 221886, 83805218, 30877084287, 11284441459641, 4113010719221412},
{1, 1636, 2010034, 2280772380, 2523761295627, 2769755537579952, 3031455813294108948, 3314879002466198503080},
{1, 4916, 18134514, 61761978300, 205103050119627, 675507759929956512, 2218696908383551468308, 7280640738500515014553320, 23884125330310241581776080853},
{1, 14757, 163358151, 1669369542291, 16633368715805358, 164364489292170484590, 1619729636032633290318498, 15947039988935644725038892138, 156958704656445989980689513610911, 1544708956416079771407327238656984139},
{1, 44281, 1470710395, 45090623244271, 1347888929379662362, 39959437240297322060278, 1181382154718570769797966170, 34895073775900019052240192095218, 1030399116864328608488320120932827143, 30423048235258853916780570577659445554071, 898225277835594788771326994531551239761914685}
		

Crossrefs

Cf. A022166.

Programs

  • Mathematica
    t[n_, m_] = If[m == 0, n!, Product[Sum[(m + 1)^i, {i, 0, k - 1}], {k, 1, n}]];
    b[n_, k_, m_] = If[n == 0, 1, t[n, m]/(t[k, m]*t[n - k, m])];
    t1[n_, k_, q_] = (1/(q - 1)^k)*Sum[(-1)^(k - j)* Binomial[k + n, k - j]*b[j + n, j, q - 1], {j, 0, k}];
    Table[Flatten[Table[Table[t1[n, k, m + 1], {k, 0, n}], {n, 0, 10}]], {m, 1, 15}]
    (* Second program: *)
    (* S stands for qStirling2 *)
    S[n_, k_, q_] /; 1 <= k <= n := S[n-1, k-1, q] + Sum[q^j, {j, 0, k-1}]* S[n-1, k, q];
    S[n_, 0, _] := KroneckerDelta[n, 0];
    S[0, k_, _] := KroneckerDelta[0, k];
    S[, , _] = 0;
    Table[S[n+k, n, 3], {n, 0, 7}, {k, 0, n}] // Flatten (* Jean-François Alcover, Mar 09 2020 *)

Formula

t1(n, k, q_) = (1/(q - 1)^k)*Sum[(-1)^(k - j)*Binomial[k + n, k -j]*q-Binomial[j + n, j, q - 1], {j, 0, k}]; q=3;m=2.