Good evening. In the notice about A011971, in the second line of comments, it is written that if P is the lower-triangular Pascal-matrix, then the triangular matrix A011971 (Bell-Aitken-Peirce triangle) is exp(P)/exp(1). I think it is not. Greetings. Roger CUCULIÈRE 35, rue d'Alsace 92110 CLICHY LA GARENNE FRANCE <rcuculiere at free.fr>