s(k)=1, where s=A030767.

Terms

a(0) =2a(1) =4a(2) =7a(3) =8a(4) =11a(5) =16a(6) =17a(7) =23a(8) =24a(9) =32a(10) =33a(11) =43a(12) =44a(13) =56a(14) =57a(15) =71a(16) =72a(17) =78a(18) =89a(19) =90a(20) =109a(21) =110a(22) =131a(23) =154a(24) =178a(25) =180a(26) =183a(27) =186a(28) =189a(29) =192