cp's OEIS Frontend

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.

Showing 1-10 of 23 results. Next

A008520 Numbers whose American English name contains the letter 'e'.

Original entry on oeis.org

0, 1, 3, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 33, 35, 37, 38, 39, 41, 43, 45, 47, 48, 49, 51, 53, 55, 57, 58, 59, 61, 63, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90
Offset: 1

Views

Author

Keywords

Comments

A085513(a(n)) > 0. - Reinhard Zumkeller, Jan 23 2015

Crossrefs

Cf. A006933 (complement), A085513.
Cf. A008519 (o), A008522 (t), A008536 (n), A008538 (s), A008540 (f), A008553 (y).

Programs

  • Haskell
    import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (any)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a008520 n = a008520_list !! (n-1)
    a008520_list = filter (T.any (== 'e') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
  • Mathematica
    A008520Q[n_]:=StringContainsQ[IntegerName[n,"Words"],"e"];Select[Range[0,200],A008520Q] (* Paolo Xausa, Aug 11 2023 *)

Extensions

Name edited by Michael De Vlieger, Aug 11 2023

A089589 Iban numbers (the letter i is banned from the English name of the number).

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 10, 11, 12, 14, 17, 20, 21, 22, 23, 24, 27, 40, 41, 42, 43, 44, 47, 70, 71, 72, 73, 74, 77, 100, 101, 102, 103, 104, 107, 110, 111, 112, 114, 117, 120, 121, 122, 123, 124, 127, 140, 141, 142, 143, 144, 147, 170, 171, 172, 173, 174, 177, 200, 201
Offset: 1

Views

Author

Eric W. Weisstein, Nov 09 2003

Keywords

Comments

Blind numbers. - Cino Hilliard, May 03 2004
There are 30276 terms, ending in 777777. - Michael S. Branicky, Aug 04 2022

Crossrefs

Cf. A006933 (ban e), A008521 (ban o), A008523 (ban t), A089590 (ban u).

Programs

  • Haskell
    import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (all)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a089589 n = a089589_list !! (n-1)
    a089589_list = filter (T.all (/= 'i') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Python
    from itertools import islice
    from num2words import num2words
    def agen(): yield from (k for k in range(10**6) if "i" not in num2words(k))
    print(list(islice(agen(), 60))) # Michael S. Branicky, Aug 04 2022

A089590 Uban numbers (the letter u is banned from the English name of the number).

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73, 75, 76, 77, 78, 79, 80, 81, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 95, 96, 97, 98, 99
Offset: 1

Views

Author

Eric W. Weisstein, Nov 09 2003

Keywords

Comments

The sequence of uban numbers first differs from A052406 (the numbers not containing the digit 4) at the term 40 (forty), which is a uban number but is not 4-less.

Crossrefs

Cf. A052406.
Cf. A006933 (ban e), A089589 (ban i), A008521 (ban o), A008523 (ban t).

Programs

  • Haskell
    import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (all)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a089590 n = a089590_list !! (n-1)
    a089590_list = filter (T.all (/= 'u') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Python
    from num2words import num2words
    from itertools import islice, product
    def ok(n): return "u" not in num2words(n)
    def agen(): # generator of terms < 10**304
        base, pows = [k for k in range(1, 1000) if ok(k)], [1]
        yield from ([0] if ok(0) else []) + base
        for e in range(3, 304, 3):
            if "u" not in num2words(10**e)[4:]:
                pows = [10**e] + pows
                for t in product([0] + base, repeat=len(pows)):
                    if t[0] == 0: continue
                    yield sum(t[i]*pows[i] for i in range(len(t)))
    print(list(islice(agen(), 100))) # Michael S. Branicky, Aug 19 2022

Extensions

a(1) = 0 prepended by Reinhard Zumkeller, Jan 23 2015

A008521 Numbers that do not contain the letter 'o'.

Original entry on oeis.org

3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 23, 25, 26, 27, 28, 29, 30, 33, 35, 36, 37, 38, 39, 50, 53, 55, 56, 57, 58, 59, 60, 63, 65, 66, 67, 68, 69, 70, 73, 75, 76, 77, 78, 79, 80, 83, 85, 86, 87, 88, 89, 90, 93, 95, 96, 97, 98, 99, 300, 303, 305, 306, 307
Offset: 1

Views

Author

Keywords

Comments

There are exactly 454 oban numbers. - Eric W. Weisstein, Nov 09 2003

Crossrefs

Cf. A006933 (ban e), A089589 (ban i), A008523 (ban t), A089590 (ban u).

Programs

  • Haskell
    import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (all)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a008521 n = a008521_list !! (n-1)
    a008521_list = filter (T.all (/= 'o') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Python
    from num2words import num2words
    afull = [k for k in range(1000) if "o" not in num2words(k)]
    print(afull[:70]) # Michael S. Branicky, Aug 18 2022

A008523 Numbers that do not contain the letter 't'.

Original entry on oeis.org

0, 1, 4, 5, 6, 7, 9, 11, 100, 101, 104, 105, 106, 107, 109, 111, 400, 401, 404, 405, 406, 407, 409, 411, 500, 501, 504, 505, 506, 507, 509, 511, 600, 601, 604, 605, 606, 607, 609, 611, 700, 701, 704, 705, 706, 707, 709, 711, 900, 901, 904, 905, 906, 907, 909, 911, 1000000, 1000001, 1000004, 1000005
Offset: 1

Views

Author

Keywords

Comments

See also A006933, the eban numbers (numbers not containing 'e'), and A089589 (the iban numbers). This sequence might correspondingly be called the "tban" numbers. - WG Zeist, Aug 31 2012

Crossrefs

Cf. A006933 (ban e), A089589 (ban i), A008521 (ban o), A089590 (ban u).
Complement of A008522.

Programs

  • Haskell
    -- import Data.Maybe (fromJust)
    import Data.Text (Text); import qualified Data.Text as T (all)
    import Text.Numeral.Grammar.Reified (defaultInflection)
    import qualified Text.Numeral.Language.EN as EN  -- see link
    a008523 n = a008523_list !! (n-1)
    a008523_list = filter (T.all (/= 't') . numeral) [0..] where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Python
    from num2words import num2words
    from itertools import islice, product
    def ok(n): return "t" not in num2words(n)
    def agen(): # generator of terms < 10**304
        base, pows = [k for k in range(1, 1000) if ok(k)], [1]
        yield from ([0] if ok(0) else []) + base
        for e in range(3, 304, 3):
            if "u" not in num2words(10**e)[4:]:
                pows = [10**e] + pows
                for t in product([0] + base, repeat=len(pows)):
                    if t[0] == 0: continue
                    yield sum(t[i]*pows[i] for i in range(len(t)))
    print(list(islice(agen(), 60))) # Michael S. Branicky, Aug 19 2022

Extensions

a(57)-a(60) from WG Zeist, Aug 31 2012

A014254 Liponombres: numbers whose French name does not contain the letter "e".

Original entry on oeis.org

1, 3, 5, 6, 8, 10, 18, 20, 23, 25, 26, 28, 1000000, 1000001, 1000003, 1000005, 1000006, 1000008, 1000010, 1000018, 1000020, 1000023, 1000025, 1000026, 1000028, 3000000, 3000001, 3000003, 3000005, 3000006, 3000008, 3000010
Offset: 1

Views

Author

Keywords

Comments

In French also called: les nombres "évites" ou "apparés".
Could also be called les nombres "epers". - Benoit Cloitre, May 05 2003
French version of eban numbers (A006933): no "e" in name of number in French - "e" perd ("e" lost)!

Examples

			a(1) = 1 ("un"), a(2) = 3 ("trois", not "dEux")
		

References

  • Georges Perec, La disparition, Editions Gallimard, Paris, 1969; English translation: A Void, Harvill, 1994. (A novel that does not use the letter "e". These numbers are not mentioned, however.)

Crossrefs

Programs

Extensions

Additional comments from Bruno Salvy (Bruno.Salvy(AT)inria.fr) and Nicolas Graner (Nicolas.Graner(AT)cri.u-psud.fr), May 11 2003
Corrected by Don Reble, Nov 19 2006
Edited by M. F. Hasler, Nov 11 2015

A054047 Numbers which can be read as (possibly different) numbers when rotated by 180 degrees (final zeros allowed).

Original entry on oeis.org

0, 1, 6, 8, 9, 10, 11, 16, 18, 19, 60, 61, 66, 68, 69, 80, 81, 86, 88, 89, 90, 91, 96, 98, 99, 100, 101, 106, 108, 109, 110, 111, 116, 118, 119, 160, 161, 166, 168, 169, 180, 181, 186, 188, 189, 190, 191, 196, 198, 199, 600, 601, 606, 608, 609, 610, 611, 616, 618
Offset: 0

Views

Author

Alain Zalmanski (alain.zalmanski(AT)cybercable.fr), Apr 28 2000

Keywords

References

  • A. Zalmanski, Some fun with figures and letters, unpublished.

Crossrefs

Extensions

Corrected and extended by James Sellers, Apr 30 2000

A072956 Turban numbers: without letters r, t, or u.

Original entry on oeis.org

1, 5, 6, 7, 9, 11, 1000000, 1000001, 1000005, 1000006, 1000007, 1000009, 1000011, 5000000, 5000001, 5000005, 5000006, 5000007, 5000009, 5000011, 6000000, 6000001, 6000005, 6000006, 6000007, 6000009, 6000011, 7000000, 7000001, 7000005, 7000006, 7000007, 7000009
Offset: 1

Views

Author

Michael Joseph Halm, Aug 13 2002

Keywords

References

  • M. J. Halm, Sequences (Re)discovered, Mpossibilities 81 (Aug. 2002).

Crossrefs

Cf. A006933 (eban numbers: without 'e'), A008521 (without 'o'), A008523 (without 't'), A008537 (without 'n'), A089590 (without 'u'), A072957 (urban numbers: without r or u), A089589 (without 'i').

Programs

  • PARI
    is(n)=!setintersect(Set(Vec(English(n))),["r","t","u"]) \\ See A052360 for English(). - M. F. Hasler, Apr 01 2019
    
  • Python
    from num2words import num2words
    from itertools import islice, product
    def ok(n): return set(num2words(n)) & {"r", "t", "u"} == set()
    def agen(): # generator of terms < 10**304
        base, pows = [k for k in range(1, 1000) if ok(k)], [1]
        yield from ([0] if ok(0) else []) + base
        for e in range(3, 304, 3):
            if set(num2words(10**e)[4:]) & {"r", "t", "u"} == set():
                pows = [10**e] + pows
                for t in product([0] + base, repeat=len(pows)):
                    if t[0] == 0: continue
                    yield sum(t[i]*pows[i] for i in range(len(t)))
    print(list(islice(agen(), 66))) # Michael S. Branicky, Aug 19 2022

A072957 Urban numbers: without 'r' or 'u'.

Original entry on oeis.org

1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 15, 16, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 50, 51, 52, 55, 56, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 72, 75, 76, 77, 78, 79, 80, 81, 82, 85, 86, 87, 88, 89, 90, 91, 92, 95, 96, 97, 98, 99, 1000000, 1000001, 1000002
Offset: 1

Views

Author

Michael Joseph Halm, Aug 13 2002

Keywords

References

  • M. J. Halm, Sequences (Re)discovered, Mpossibilities 81 (Aug. 2002).

Crossrefs

Cf. A006933 (eban numbers: without 'e'), A008521 (without 'o'), A008523 (without 't'), A008537 (without 'n'), A089590 (without 'u'), A072956 (turban numbers: without r, t or u), A089589 (without 'i').

Programs

  • PARI
    is(n)=!setintersect(Set(Vec(English(n))),["r","u"]) \\ See A052360 for English(). - M. F. Hasler, Apr 01 2019
    /* Alternate code, not using English(): (valid for 1 <= n < one trillion, which should be forbidden due to the 'r' but returns 1) */
    is(n)={setintersect( Set(digits(n)), [3,4]) && return; !while(n=divrem(n,10^6), n[2]<100||return; n=n[1])} \\ M. F. Hasler, Apr 01 2019
    
  • Python
    from num2words import num2words
    from itertools import islice, product
    def ok(n): return set(num2words(n)) & {"r", "u"} == set()
    def agen(): # generator of terms < 10**304
        base, pows = [k for k in range(1, 1000) if ok(k)], [1]
        yield from ([0] if ok(0) else []) + base
        for e in range(3, 304, 3):
            if set(num2words(10**e)[4:]) & {"r", "u"} == set():
                pows = [10**e] + pows
                for t in product([0] + base, repeat=len(pows)):
                    if t[0] == 0: continue
                    yield sum(t[i]*pows[i] for i in range(len(t)))
    print(list(islice(agen(), 66))) # Michael S. Branicky, Aug 19 2022

Extensions

Missing term 52 inserted by Michael S. Branicky, Aug 19 2022

A085513 Number of "e"s in n (in English).

Original entry on oeis.org

1, 1, 0, 2, 0, 1, 0, 2, 1, 1, 1, 3, 2, 2, 2, 2, 2, 4, 3, 3, 1, 2, 1, 3, 1, 2, 1, 3, 2, 2, 0, 1, 0, 2, 0, 1, 0, 2, 1, 1, 0, 1, 0, 2, 0, 1, 0, 2, 1, 1, 0, 1, 0, 2, 0, 1, 0, 2, 1, 1, 0, 1, 0, 2, 0, 1, 0, 2, 1, 1, 2, 3, 2, 4, 2, 3, 2, 4, 3, 3, 1, 2, 1, 3, 1, 2, 1, 3, 2, 2, 1, 2, 1, 3, 1, 2, 1, 3, 2, 2
Offset: 0

Views

Author

Samuel Thompson (samuelt(AT)ugcs.caltech.edu), Jul 03 2003

Keywords

Comments

a(A006933(n)) = 0; a(A008520(n)) > 0. - Reinhard Zumkeller, Jan 23 2015
a(A006933(n)) = 0; a(A008520(n)) > 0; a(A121065(n)) = n and a(m) != n for m < A121065(n). - Reinhard Zumkeller, Jan 24 2015

Examples

			a(123) = 5 because "onE hundrEd twEnty-thrEE" has 5 e's.
		

Crossrefs

Programs

  • 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
    a085513 = length . filter (== 'e') . T.unpack . numeral where
       numeral :: Integer -> Text
       numeral = fromJust . EN.gb_cardinal defaultInflection
    -- Reinhard Zumkeller, Jan 23 2015
    
  • Mathematica
    StringCount[IntegerName/@Range[0,99],"e"] (* Ivan N. Ianakiev, Mar 25 2017 *)
  • Python
    from num2words import num2words
    def A085513(n):
        return num2words(n).count('e') # Chai Wah Wu, Dec 20 2019
Showing 1-10 of 23 results. Next