The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A006933 'Eban' numbers (the letter 'e' is banned!). (Formerly M1030) 24
 2, 4, 6, 30, 32, 34, 36, 40, 42, 44, 46, 50, 52, 54, 56, 60, 62, 64, 66, 2000, 2002, 2004, 2006, 2030, 2032, 2034, 2036, 2040, 2042, 2044, 2046, 2050, 2052, 2054, 2056, 2060, 2062, 2064, 2066, 4000, 4002, 4004, 4006, 4030, 4032, 4034, 4036, 4040, 4042, 4044, 4046, 4050, 4052, 4054, 4056, 4060, 4062, 4064, 4066, 6000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Invented by N. J. A. Sloane circa 1990. Theorem (N. J. A. Sloane): in English every odd number contains an 'e'. The first number that would appear in the British Eban list but not the American list is 2*10^21. - Douglas Boffey, Jun 21 2012 A085513(a(n)) = 0. - Reinhard Zumkeller, Jan 23 2015 REFERENCES J. C. Hernandez et al., "Characterization of Eban numbers", pp. 197-200, Journal of Recreational Mathematics, 31 (3) 2002-2003. Georges Perec, La disparition, Editions Gallimard, Paris, 1969; English translation: A Void, Harvill, 1994. (A novel that does not use the letter "e".) Georges Perec, Les Revenentes [a novel in which the only vowel that appears is 'e']. - From Simon Plouffe, Mar 12 2010 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 Roel and Bas van Dijk, Numerals package, Hackage (Haskell packages) Brady Haran and N. J. A. Sloane, What Number Comes Next? (2018), Numberphile video Eric Weisstein's World of Mathematics, Eban Number Index entries for sequences related to number of letters in n EXAMPLE 2052 is in the sequence because written out in English words, "two thousand fifty-two", it does not contain a single instance of the letter E. 2053 (two thousand fifty-three) is not in the sequence because written out it contains two instances of E. PROG (Magma) [ n : n in [1..100] | forall{ i : i in [1..#seq] | seq[i] in eban[(i-1)mod 3+1]} where seq is Intseq(n) ] where eban is [[0, 2, 4, 6], [0, 3, 4, 5, 6], [0]]; // Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006 (Haskell) import Data.Maybe (fromJust) import Data.Text (Text); import qualified Data.Text as T (unpack) import Text.Numeral.Grammar.Reified (defaultInflection) import qualified Text.Numeral.Language.EN as EN -- see link a006933 n = a006933_list !! (n-1) a006933_list = filter (T.all (/= 'e') . numeral) [0..] where numeral :: Integer -> Text numeral = fromJust . EN.gb_cardinal defaultInflection -- Reinhard Zumkeller, Jan 23 2015 (Python) from num2words import num2words [n for n in range(6001) if 'e' not in num2words(n)] # Indranil Ghosh, Jul 05 2017 (PARI) is(n)=!setsearch(Set(Vec(English(n))), "e") \\ See A052360 for English(). - M. F. Hasler, Apr 01 2019 CROSSREFS Cf. A082504. Cf. A085513, A008520 (complement), A008521 (ban o), A008523 (ban t), A089589 (ban i), A089590 (ban u), A014254 (a French version), A287876 (a Hebrew version). Cf. A008537 (without 'n'), A072956 (turban numbers: without r, t or u), A072957 (urban numbers: without r or u), A089589 (without 'i'). Sequence in context: A284919 A279419 A077633 * A046847 A339759 A121069 Adjacent sequences: A006930 A006931 A006932 * A006934 A006935 A006936 KEYWORD word,nonn AUTHOR N. J. A. Sloane EXTENSIONS More terms from WG Zeist, Aug 28 2012 More cross-references from M. F. Hasler, Apr 01 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 9 06:42 EDT 2023. Contains 363168 sequences. (Running on oeis4.)