2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73829Kostka numbers and Littlewood-Richardson coefficients play an essential role in the representation theory of the symmetric groups and the special linear groups. There has been a significant amount of interest in their computation. The issue of their computational complexity has been a question of folklore, but was asked explicitly by E. Rassart. We prove that the computation of either quantity is #P-complete. The reduction to computing Kostka numbers, is from the #P-complete problem of counting the number of 2 x k contingency tables having given row and column sums. The main ingredient in this reduction is a correspondence discovered by D. E. Knuth. The reduction to the problem of computing Littlewood-Richardson coefficients is from that of computing Kostka numbers.10 pages, 5 figuresCombinatorics05E15; 68Q17text