a(n) = Sum_{k=1..n} (-1)^isprime(k)*10^k.
A243106
a(n) = Sum_{k=1..n} (-1)^isprime(k)*10^k.
Terms
- a(0) =10a(1) =-90a(2) =-1090a(3) =8910a(4) =-91090a(5) =908910a(6) =-9091090a(7) =90908910a(8) =1090908910a(9) =11090908910a(10) =-88909091090a(11) =911090908910
External references
- oeis: A243106