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 A073418 Useless numbers: numbers written in English without any of the letters e, s or u. 0
 2, 30, 32, 40, 42, 50, 52, 2000000, 2000002, 2000030, 2000032, 2000040, 2000042, 2000050, 2000052, 30000000, 30000002, 30000030, 30000032, 30000040, 30000042, 30000050, 30000052, 32000000, 32000002, 32000030, 32000032, 32000040, 32000042, 32000050, 32000052 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS After a(7), the sequence contains only terms of the form a(i) * 10^(3*k) and a(i) * 10^(3*k) + a(j) for 1 <= i, j <= 7, where the name of 10^(3*k) is useless, e.g., 10^6 (million), 10^9 (billion), 10^12 (trillion), 10^27 (octillion), 10^30 (nonillion), ... (see links for large number names). - Michael S. Branicky, Jan 01 2021 LINKS M. J. Halm, Sequences (Re)discovered, Mpossibilities 81 (Aug. 2002). Eric Weisstein's World of Mathematics, Large Number Wikipedia, Names of Large Numbers EXAMPLE a(2) = 30 because 30 is the second integer without an e, s or u in its English name. CROSSREFS Sequence in context: A228937 A071056 A075716 * A022377 A145290 A343930 Adjacent sequences: A073415 A073416 A073417 * A073419 A073420 A073421 KEYWORD nonn,word AUTHOR Michael Joseph Halm, Aug 23 2002 EXTENSIONS Removed 'ninety' and 'ninety two' from the sequence which clearly include the letter E. Likewise removed 'two hundrEd' and others. Inserted 'thirty' and 'thirty-two'. - Freddie Noble, Jan 01 2021 a(16)-a(31) from Michael S. Branicky, Jan 01 2021 STATUS approved

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Last modified March 31 17:52 EDT 2023. Contains 361670 sequences. (Running on oeis4.)