Position of n-th 7 in A007376.

Terms

a(0) =7a(1) =25a(2) =45a(3) =65a(4) =85a(5) =105a(6) =125a(7) =130a(8) =132a(9) =134a(10) =136a(11) =138a(12) =140a(13) =142a(14) =144a(15) =145a(16) =146a(17) =148a(18) =165a(19) =185a(20) =213a(21) =243a(22) =273a(23) =303a(24) =333a(25) =363a(26) =393a(27) =401a(28) =404a(29) =407