{ "id": "1406.1589", "version": "v1", "published": "2014-06-06T05:58:04.000Z", "updated": "2014-06-06T05:58:04.000Z", "title": "On $t$-extensions of the Hankel determinants of certain automatic sequences", "authors": [ "Hao Fu", "Guo-Niu Han" ], "categories": [ "math.CO", "math.NT" ], "abstract": "In 1998, Allouche, Peyri\\`ere, Wen and Wen considered the Thue--Morse sequence, and proved that all the Hankel determinants of the period-doubling sequence are odd integral numbers. We speak of $t$-extension when the entries along the diagonal in the Hankel determinant are all multiplied by~$t$. Then we prove that the $t$-extension of each Hankel determinant of the period-doubling sequence is a polynomial in $t$, whose leading coefficient is the {\\it only one} to be an odd integral number. Our proof makes use of the combinatorial set-up developed by Bugeaud and Han, which appears to be very suitable for this study, as the parameter $t$ counts the number of fixed points of a permutation. Finally, we prove that all the $t$-extensions of the Hankel determinants of the regular paperfolding sequence are polynomials in $t$ of degree less than or equal to $3$.", "revisions": [ { "version": "v1", "updated": "2014-06-06T05:58:04.000Z" } ], "analyses": { "subjects": [ "05A05", "05A10", "05A15", "05A19", "11B50", "11B65", "11B85", "15A15" ], "keywords": [ "hankel determinant", "automatic sequences", "odd integral number", "period-doubling sequence", "polynomial" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1406.1589F" } } }