Irregular triangle read by rows: T(n,k) is the number of endofunctions on [n] whose fourth-smallest component has size exactly k; n >= 0, 0 <= k <= max(0,n-3).

A350276

Irregular triangle read by rows: T(n,k) is the number of endofunctions on [n] whose fourth-smallest component has size exactly k; n >= 0, 0 <= k <= max(0,n-3).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =27a(4) =255a(5) =1a(6) =3094a(7) =1a(8) =30a(9) =45865a(10) =46a(11) =405a(12) =340a(13) =803424a(14) =659a(15) =3780a(16) =10710a(17) =4970a(18) =16239720a(19) =12867a(20) =48405a(21) =209440a(22) =178920a(23) =87864a(24) =372076163a(25) =284785a(26) =1225665a(27) =3005940a(28) =5457060a(29) =3558492

External references