List the positions of all digits 7 in the concatenation of all terms, not necessarily in order. This is the lexicographically earliest such sequence.
A210421
List the positions of all digits 7 in the concatenation of all terms, not necessarily in order. This is the lexicographically earliest such sequence.
Terms
- a(0) =2a(1) =7a(2) =4a(3) =70a(4) =8a(5) =77a(6) =11a(7) =71a(8) =15a(9) =72a(10) =19a(11) =73a(12) =23a(13) =74a(14) =27a(15) =75a(16) =26a(17) =33a(18) =76a(19) =37a(20) =78a(21) =36a(22) =43a(23) =79a(24) =47a(25) =700a(26) =46a(27) =54a(28) =701a(29) =59
External references
- oeis: A210421