a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3,4 and 5, at least one of digits 6,7 and at least one of digits 8,9.
A126645
a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3,4 and 5, at least one of digits 6,7 and at least one of digits 8,9.
Terms
- a(0) =5a(1) =21a(2) =77a(3) =261a(4) =845a(5) =2661a(6) =8237a(7) =25221a(8) =76685a(9) =232101a(10) =700397a(11) =2109381a(12) =6344525a(13) =19066341a(14) =57264557a(15) =171924741a(16) =516036365a(17) =1548633381a(18) =4646948717a(19) =13942943301a(20) =41833024205a(21) =125507461221a(22) =376539160877
External references
- oeis: A126645