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.

A042415 Denominators of continued fraction convergents to sqrt(735).

Original entry on oeis.org

1, 9, 487, 4392, 237655, 2143287, 115975153, 1045919664, 56595637009, 510406652745, 27618554885239, 249077400619896, 13477798188359623, 121549261095856503, 6577137897364610785, 59315790337377353568, 3209629816115741703457
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Denominator[Convergents[Sqrt[735], 20]] (* Harvey P. Dale, Oct 11 2011 *)
    CoefficientList[Series[(1 + 9 x - x^2)/(x^4 - 488 x^2 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 21 2014 *)

Formula

G.f.: -(x^2-9*x-1) / (x^4-488*x^2+1). - Colin Barker, Dec 12 2013

Extensions

More terms from Colin Barker, Dec 12 2013

A024224 a(n) = floor((4th elementary symmetric function of S(n))/(3rd elementary symmetric function of S(n))), where S(n) = {first n+3 positive integers congruent to 1 mod 3}.

Original entry on oeis.org

0, 2, 4, 7, 11, 16, 22, 28, 35, 43, 51, 60, 70, 81, 93, 105, 118, 132, 146, 161, 177, 194, 212, 230, 249, 269, 289, 310, 332, 355, 379, 403, 428, 454, 480, 507, 535, 564, 594, 624, 655, 687, 719, 752, 786, 821, 857, 893, 930, 968, 1006, 1045, 1085, 1126, 1168, 1210, 1253, 1297, 1341, 1386, 1432
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    [(3*n^2+5*n-6) div 8: n in [1..70]]; // Vincenzo Librandi, Dec 11 2015
  • Maple
    seq(floor((3*n^2 + 5*n - 6)/8), n=1..100); # Robert Israel, Dec 10 2015
  • Mathematica
    S[n_] := 3 Range[0, n + 2] + 1; Table[Floor[SymmetricPolynomial[4, S@ n]/SymmetricPolynomial[3, S@ n]], {n, 61}] (* Michael De Vlieger, Dec 10 2015 *)
  • PARI
    concat(0, Vec(x^2*(2-2*x+3*x^2-2*x^3+3*x^4-2*x^5+2*x^6-x^7)/((1-x)^3*(1+x^2)*(1+x^4)) + O(x^100))) \\ Colin Barker, Dec 10 2015
    
  • PARI
    a(n) = (3*n^2 + 5*n - 6)\8; \\ Altug Alkan, Dec 10 2015
    

Formula

G.f.: x^2*(2-2*x+3*x^2-2*x^3+3*x^4-2*x^5+2*x^6-x^7) / ((1-x)^3*(1+x^2)*(1+x^4)). - Colin Barker, Dec 10 2015
From Robert Israel, Dec 10 2015: (Start)
a(n) = floor(A024214(n+1)/A024213(n+1)).
a(n) = floor((3 n^2 + 5 n - 6)/8).
a(8*k+j) = 24*k^2 + (5 + 6*j) k + b(j), where b(j) = -1,0,2,4,7,11,16,22 for j = 0..7. (End)

Extensions

More terms from Michael De Vlieger, Dec 10 2015
Showing 1-2 of 2 results.