1,1

Primality up to Catalan[5885]-1 proved by PrimeForm.

Catalan[25]-1=50!/25!/26!-1=4861946401451 is prime.

Cf. A000108, A053429.

Sequence in context: A030751 A152870 A087947 this_sequence A037354 A035065 A035067

Adjacent sequences: A053424 A053425 A053426 this_sequence A053428 A053429 A053430

nonn

David Broadhurst (D.Broadhurst(AT)open.ac.uk), Jan 10 2000