Triangle read by rows: T(n,k) is the number of labeled commutative magmas with n elements and k idempotents.

A391482

Triangle read by rows: T(n,k) is the number of labeled commutative magmas with n elements and k idempotents.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =2a(4) =4a(5) =2a(6) =216a(7) =324a(8) =162a(9) =27a(10) =331776a(11) =442368a(12) =221184a(13) =49152a(14) =4096a(15) =10000000000a(16) =12500000000a(17) =6250000000a(18) =1562500000a(19) =195312500a(20) =9765625a(27) =470184984576

External references