Number of cyclotomic cosets of 7 mod 10^n.

Terms

a(0) =4a(1) =27a(2) =93a(3) =265a(4) =685a(5) =1265a(6) =2005a(7) =2905a(8) =3965a(9) =5185a(10) =6565a(11) =8105a(12) =9805a(13) =11665a(14) =13685a(15) =15865a(16) =18205a(17) =20705a(18) =23365a(19) =26185a(20) =29165a(21) =32305a(22) =35605a(23) =39065a(24) =42685a(25) =46465a(26) =50405a(27) =54505a(28) =58765a(29) =63185