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 1-2 of 2 results.

A000861 Numbers ending with a vowel in American English.

Original entry on oeis.org

0, 1, 2, 3, 5, 9, 12, 21, 22, 23, 25, 29, 31, 32, 33, 35, 39, 41, 42, 43, 45, 49, 51, 52, 53, 55, 59, 61, 62, 63, 65, 69, 71, 72, 73, 75, 79, 81, 82, 83, 85, 89, 91, 92, 93, 95, 99, 101, 102, 103, 105, 109, 112, 121, 122, 123, 125, 129, 131, 132, 133, 135, 139, 141, 142
Offset: 1

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Author

Keywords

Comments

The German name of n ends in a vowel iff n==2 or n==3 (mod 100), so the German analog of this sequence would be {2, 3, 102, 103, 202, 203, ...}. - M. F. Hasler, Sep 20 2014

Crossrefs

Cf. A247359 (complement), A152592 (characteristic fct of the complement), A059437 (a variant of the latter: vowels or "y").
Cf. A247361 (French analog) and A247360 (complement).

Programs

  • PARI
    print1(0",");for(n=1,3,for(k=10^(n-1),10^n-1,m100=k%100;m10=k%10;if(m100==12 || ((m100>20 || m100<10) && ((m10==1)||(m10==2)||(m10==3)||(m10==5)||(m10==9))),print1(k",")))) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006
    
  • PARI
    is(n,S=[1,2,3,5,9,12])=setsearch(S,if(n%100>19,n%10,n%100))||!n \\ Add 0 in S (and optionally remove trailing ||...) for the A059437 variant. Add "Set()" around [...] for PARI versions < 2.6. - M. F. Hasler, Sep 14 2014

Formula

From Chai Wah Wu, Apr 18 2024: (Start)
a(n) = a(n-1) + a(n-46) - a(n-47) for n > 48.
G.f.: x^2*(x^46 + 4*x^45 + 2*x^44 + x^43 + x^42 + 2*x^41 + 4*x^40 + 2*x^39 + x^38 + x^37 + 2*x^36 + 4*x^35 + 2*x^34 + x^33 + x^32 + 2*x^31 + 4*x^30 + 2*x^29 + x^28 + x^27 + 2*x^26 + 4*x^25 + 2*x^24 + x^23 + x^22 + 2*x^21 + 4*x^20 + 2*x^19 + x^18 + x^17 + 2*x^16 + 4*x^15 + 2*x^14 + x^13 + x^12 + 2*x^11 + 4*x^10 + 2*x^9 + x^8 + x^7 + 9*x^6 + 3*x^5 + 4*x^4 + 2*x^3 + x^2 + x + 1)/(x^47 - x^46 - x + 1). (End)

Extensions

Corrected by Logan K. Young (lkyfella(AT)yahoo.com), Mar 19 2005
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 20 2006

A247362 Interleave A000861 and A247359, numbers ending in a vowel resp. consonant in English.

Original entry on oeis.org

0, 4, 1, 6, 2, 7, 3, 8, 5, 10, 9, 11, 12, 13, 21, 14, 22, 15, 23, 16, 25, 17, 29, 18, 31, 19, 32, 20, 33, 24, 35, 26, 39, 27, 41, 28, 42, 30, 43, 34, 45, 36, 49, 37, 51, 38, 52, 40, 53, 44, 55, 46, 59, 47, 61, 48, 62, 50, 63, 54, 65, 56, 69, 57, 71, 58, 72
Offset: 0

Views

Author

M. F. Hasler, Sep 14 2014

Keywords

Comments

A permutation of the nonnegative integers.
See A247361 for the analog permutation of the positive integers, starting with a(1)=1.

Crossrefs

Showing 1-2 of 2 results.