Expansion of 1/((1-x)(1-3x)(1-5x)(1-6x)).

Terms

a(0) =1a(1) =15a(2) =148a(3) =1218a(4) =9079a(5) =63693a(6) =429346a(7) =2815296a(8) =18097717a(9) =114645531a(10) =718257904a(11) =4461736734a(12) =27532164115a(13) =169004094729