This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A321998 #7 Nov 24 2018 01:24:19 %S A321998 91,93,101,107,109,115,141,147,149,155,157,163,166,173,174,178,179, %T A321998 205,206,210,211,214,218,221,222,223,226,227,229,230,231,233,234,235, %U A321998 236,237,243,245,251,261,267,269,275,276,277,278,279,281,282,283,285,286,287,290,291 %N A321998 Numbers that cannot be written using eight 8's and operations +, -, * and/or /. Complement of A258069. %C A321998 A258069 contains all nonnegative integers up to 90, which motivates to list the complement, even though A258069 is finite and its complement, this sequence, contains all integers above 2359296 except for 4194304 and 16777216. (These are the last three terms of A258069.) %Y A321998 Cf. A258069 (complement), A171826, A171827, A171828, A171829, A258068, A258070, A258071 (analog for 3, ..., 10). %Y A321998 Cf. A182002, A258097. %K A321998 nonn %O A321998 1,1 %A A321998 _M. F. Hasler_, Nov 23 2018