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 1-4 of 4 results.

A121013 Denominators of partial alternating sums of Catalan numbers scaled by powers of 1/(11^2) = 1/121.

Original entry on oeis.org

1, 121, 14641, 1771561, 214358881, 25937424601, 285311670611, 34522712143931, 4177248169415651, 505447028499293771, 672749994932560009201, 81402749386839761113321, 9849732675807611094711841
Offset: 0

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Author

Wolfdieter Lang, Aug 16 2006

Keywords

Comments

This is the second member (p=2) of the fourth (normalized) p-family of partial sums of the normalized scaled Catalan series CsnIV(p):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..infinity) with limit L(2*p+1)*(-F(2*p+2) + F(2*p+1)*phi) = L(2*p+1)/phi^(2*p+1), where C(n)=A000108(n) (Catalan), F(n)= A000045(n) (Fibonacci), L(n) = A000032(n) (Lucas) and phi:=(1+sqrt(5))/2 (golden section).
The partial sums of the above mentioned fourth p-family are rIV(p;n):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..n), n>=0, for p=1,...
For more details on this p-family and the other three ones see the W. Lang links under A120996 and A121012.

Examples

			Rationals r(n): [1, 120/121, 14522/14641, 1757157/1771561, 212616011/214358881, 25726537289/25937424601,...].

Crossrefs

The first member is A120794/A120785. The third member is A121498/A121499.

Formula

a(n)=denominator(r(n)) with r(n) := rIV(p=2,n) = sum(((-1)^k)*C(k)/L(2*2+1)^(2*k), k=0..n), with L(5)=11 and C(k):=A000108(k) (Catalan). The rationals r(n) are given in lowest terms.

A120794 Numerators of partial sums of Catalan numbers scaled by powers of -1/16.

Original entry on oeis.org

1, 15, 121, 3867, 30943, 495067, 3960569, 253475987, 2027808611, 32444935345, 259559486959, 8305903553295, 66447228478363, 1063155655468083, 8505245244078969, 1088671391232413187
Offset: 0

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Author

Wolfdieter Lang, Jul 20 2006

Keywords

Comments

From the expansion of sqrt(1+1/4) = 1+(1/8)*Sum_{k>=0} C(k)/(-16)^k one has, with the partial sums r(n) are defined below, r := lim_{n->oo} r(n) = 4*(sqrt(5)-2) = 4*(2*phi-3) = 0.944271909...
Denominators coincide with the listed numbers of A120785 but may differ for higher n values.
This is the first member (p=1) of the fourth family of scaled Catalan sums with limits in Q(sqrt(5)). See the W. Lang link under A120996.

Examples

			Rationals r(n): [1, 15/16, 121/128, 3867/4096, 30943/32768, 495067/524288, 3960569/4194304,...].

Links

Crossrefs

The second member (p=2) of this p-family is A121012/A121013.

Formula

a(n)=numerator(r(n)), with the rationals r(n):=Sum_{k=0..n} ((-1)^k)*C(k)/16^k with C(k):=A000108(k) (Catalan numbers). Rationals r(n) are taken in lowest terms.

A121498 Numerators of partial alternating sums of Catalan numbers scaled by powers of 1/(29^2) = 1/841.

Original entry on oeis.org

1, 840, 706442, 594117717, 499653000011, 420208173009209, 353395073500744901, 297205256814126461312, 249949620980680353964822, 210207631244752177684410440, 176784617876836581432589196836
Offset: 0

Views

Author

Wolfdieter Lang, Aug 16 2006

Keywords

Comments

Denominators are given under A121499.
This is the third member (p=3) of the fourth (normalized) p-family of partial sums of normalized scaled Catalan series CsnIV(p):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..infinity) with limit L(2*p+1)*(-F(2*p+2) + F(2*p+1)*phi) = L(2*p+1)/phi^(2*p+1), with C(n)=A000108(n) (Catalan), F(n)= A000045(n) (Fibonacci), L(n) = A000032(n) (Lucas) and phi:=(1+sqrt(5))/2 (golden section).
The partial sums of the above mentioned fourth p-family are rIV(p;n):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..n), n>=0, for p=1,...
For more details on this p-family and the other three ones see the W. Lang link under A120996.

Examples

			Rationals r(n): [1, 840/841, 706442/707281, 594117717/594823321,
499653000011/500246412961, 420208173009209/420707233300201,...].

Links

Crossrefs

The second member (p=2) of this p-family is A121012/A121013.

Programs

  • Maple
    The limit lim_{n->infinity}(r(n) := rIV(2;n)) = 29*(-21 + 13*phi) = 29/phi^7 = 0.998813758709 (maple10, 10 digits).

Formula

a(n)=numerator(r(n)) with r(n) := rIV(p=3,n) = sum(((-1)^k)*C(k)/L(2*3+1)^(2*k),k=0..n), with L(7)=29 and C(k):=A000108(k) (Catalan). The rationals r(n) are given in lowest terms.

A121499 Denominators of partial alternating sums of Catalan numbers scaled by powers of 1/(29^2) = 1/841.

Original entry on oeis.org

1, 841, 707281, 594823321, 500246412961, 420707233300201, 353814783205469041, 297558232675799463481, 250246473680347348787521, 210457284365172120330305161, 176994576151109753197786640401
Offset: 0

Views

Author

Wolfdieter Lang, Aug 16 2006

Keywords

Comments

Numerators are given under A121498.
This is the third member (p=3) of the fourth (normalized) p-family of partial sums of normalized scaled Catalan series CsnIV(p):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..infinity) with limit L(2*p+1)*(-F(2*p+2) + F(2*p+1)*phi) = L(2*p+1)/phi^(2*p+1), with C(n)=A000108(n) (Catalan), F(n)= A000045(n) (Fibonacci), L(n) = A000032(n) (Lucas) and phi:=(1+sqrt(5))/2 (golden section).
The partial sums of the above mentioned fourth p-family are rIV(p;n):=sum(((-1)^k)*C(k)/L(2*p+1)^(2*k),k=0..n), n>=0, for p=1,...
For more details on this p-family and the other three ones see the W. Lang links under A120996 and A121498.

Examples

			Rationals r(n): [1, 840/841, 706442/707281, 594117717/594823321,
499653000011/500246412961, 420208173009209/420707233300201,...].

Links

Crossrefs

The second member (p=2) of this p-family is A121012/A121013.

Formula

a(n)=denominator(r(n)) with r(n) := rIV(p=3,n) = sum(((-1)^k)*C(k)/L(2*3+1)^(2*k),k=0..n), with L(7)=29 and C(k):=A000108(k) (Catalan). The rationals r(n) are given in lowest terms.
Showing 1-4 of 4 results.

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