Neil Sorry. A107332 : (-1)Sigma exists already on OEIS. I should have searched it. Surely I had not submitted it, but you submitted it as A049060 . Yasutoshi -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://list.seqfan.eu/pipermail/seqfan/attachments/20050526/91f1da87/attachment.htm>