Numbers that require exactly 8 iterations to determine that they are happy or not (A007770 and A031177).

A193996

Numbers that require exactly 8 iterations to determine that they are happy or not (A007770 and A031177).

Terms

    a(0) =4a(1) =16a(2) =20a(3) =37a(4) =42a(5) =58a(6) =89a(7) =145a(8) =78999a(9) =79899a(10) =79989a(11) =79998a(12) =87999a(13) =89799a(14) =89979a(15) =89997a(16) =97899a(17) =97989a(18) =97998a(19) =98799a(20) =98979a(21) =98997a(22) =99789a(23) =99798a(24) =99879a(25) =99897a(26) =99978a(27) =99987a(28) =378999a(29) =379899

External references