Number of n-digit primes whose sum of digits is 7.

Terms

a(0) =1a(1) =2a(2) =7a(3) =20a(4) =28a(5) =58a(6) =95a(7) =154a(8) =226a(9) =278a(10) =403a(11) =570a(12) =734a(13) =949a(14) =1200a(15) =1515a(16) =1931a(17) =2328a(18) =2908a(19) =3529a(20) =4196a(21) =5034a(22) =5800a(23) =6870a(24) =7871a(25) =9132a(26) =10574a(27) =12359a(28) =14005a(29) =15871