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A006933 `Eban' numbers (the letter `e' is banned!).
(Formerly M1030)
9
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]

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 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

Table of n, a(n) for n=1..60.

Author?, What comes next? in Science News for Kids.

Eric Weisstein's World of Mathematics, Eban Number

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]]; - from Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006

CROSSREFS

Cf. A082504.

Sequence in context: A106274 A204661 A077633 * A046847 A121069 A100838

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

STATUS

approved

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Last modified October 21 16:17 EDT 2014. Contains 248377 sequences.