Positions of 3's in A347381.

Terms

a(0) =7a(1) =10a(2) =11a(3) =14a(4) =16a(5) =18a(6) =25a(7) =27a(8) =39a(9) =45a(10) =63a(11) =77a(12) =81a(13) =99a(14) =105a(15) =135a(16) =182a(17) =270a(18) =819a(19) =1365a(20) =1392a(21) =1638a(22) =4250a(23) =15631a(24) =21275a(25) =63767a(26) =122944a(27) =161257a(28) =203203a(29) =446369