Number of n-digit squares which contain the string "666" but not "6666".

A102832

Number of n-digit squares which contain the string "666" but not "6666".

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =3a(7) =21a(8) =78a(9) =302a(10) =1139a(11) =4156a(12) =14791a(13) =52529a(14) =183565a(15) =635691a(16) =2183533a(17) =7314869a(18) =25303217

External references