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

Terms

a(0) =1a(1) =7a(2) =28a(3) =84a(4) =210a(5) =462a(6) =924a(7) =1716a(8) =3003a(9) =5004a(10) =7995a(11) =12306a(12) =18312a(13) =26418a(14) =37038a(15) =50568a(16) =67353a(17) =87648a(18) =111573a(19) =139068a(20) =169863a(21) =203463a(22) =239148a(23) =275988a(24) =312873a(25) =348558a(26) =381723a(27) =411048a(28) =435303a(29) =453438