Seqfans: I think they're typos, in A101984: 134 should be 135; 245 should be 246. Can someone double-check? I don't know PARI, but maybe that last print statement should print b[x+1] instead of b[x]+1. (Maybe it was copied from A101983.) I suspect also A101985's PARI. -- Don Reble djr at nk.ca