Number of compositions of 7*n-5 into parts 1 and 7.

Terms

a(0) =1a(1) =4a(2) =17a(3) =83a(4) =413a(5) =2037a(6) =10010a(7) =49183a(8) =241722a(9) =1188097a(10) =5839638a(11) =28702296a(12) =141073905a(13) =693388850a(14) =3408058991a(15) =16750869834a(16) =82331801783a(17) =404667078256