Position of n-th 7 in A031076.

Terms

a(0) =7a(1) =24a(2) =42a(3) =60a(4) =78a(5) =96a(6) =114a(7) =117a(8) =119a(9) =121a(10) =123a(11) =125a(12) =127a(13) =129a(14) =131a(15) =132a(16) =133a(17) =150a(18) =176a(19) =203a(20) =230a(21) =257a(22) =284a(23) =311a(24) =338a(25) =343a(26) =346a(27) =349a(28) =352a(29) =355