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.

A368065 a(n) = Product_{i=1..n, j=1..n} (i^2 + 5*i*j + j^2).

Original entry on oeis.org

1, 7, 44100, 3210672937500, 12804360424787610000000000, 8591751256288909159255104643281750000000000, 2333034616280404811605303958158227652934766912996000000000000000000
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 10 2023

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[i^2 + 5*i*j + j^2, {i, 1, n}, {j, 1, n}], {n, 0, 7}]

Formula

a(n) ~ c * 7^(7*n*(n+1)/2) * ((5-sqrt(21))/2)^(sqrt(21)*n*(n+1)/2) * n^(2*n^2 - 4/3) / exp(3*n^2), where c = A368069.

A368064 a(n) = Product_{i=1..n, j=1..n} (i^2 + 4*i*j + j^2).

Original entry on oeis.org

1, 6, 24336, 870746557824, 1311726482483997806493696, 256433546267136937832915286844640487014400, 15678550451426175377500759401206644047210595564950427820202393600
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 10 2023

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[i^2 + 4*i*j + j^2, {i, 1, n}, {j, 1, n}], {n, 0, 7}]

Formula

a(n) ~ 2^((3+sqrt(3))*n*(n+1) + (sqrt(3)-1)/6) * 3^(3*n*(n+1) + 13/24) * n^(2*n^2 - 7/6) / (Gamma(1/3)^(1/2) * Gamma(1/4)^(1/3) * Pi^(7/12) * (1 + sqrt(3))^((6*n*(n+1) + 1)/sqrt(3) - 1/2) * exp(3*n^2)).

A368067 a(n) = Product_{i=1..n, j=1..n} (i^2 + 3*i*j + j^2).

Original entry on oeis.org

1, 5, 12100, 188898484500, 91554454518735288960000, 4263420404009649597344435073399120000000, 46073465749493255153019723901007197815549903333795840000000000
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 10 2023

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[i^2 + 3*i*j + j^2, {i, 1, n}, {j, 1, n}], {n, 0, 7}]

Formula

a(n) ~ 5^(5*n*(n+1)/2 + 1/2) * n^(2*n^2 - 1) / (2 * Pi * exp(3*n^2) * phi^(sqrt(5)*(n*(n+1) + 1/6) - 1/2)), where phi = A001622 is the golden ratio.

A368069 Decimal expansion of a constant related to the asymptotics of A368065.

Original entry on oeis.org

3, 7, 4, 9, 8, 8, 6, 7, 5, 2, 4, 8, 9, 4, 8, 7, 7, 5, 4, 2, 0, 4, 4, 2, 8, 3, 8, 9, 9, 1, 3, 1, 0, 9, 1, 5, 2, 4, 9, 0, 9, 9, 6, 8, 2, 6, 9, 7, 5, 8, 6, 3, 4, 6, 6, 1, 6, 0, 9, 3, 7, 6, 3, 1, 8, 6, 1, 8, 3, 4, 1, 2, 0, 7, 9, 1, 8, 5, 4, 7, 1, 9, 0, 7, 9, 9, 9, 3, 7, 7, 0, 3, 7, 2, 6, 9, 1, 0, 4, 0, 4, 2, 3, 0, 5, 8
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 10 2023

Keywords

Examples

			0.374988675248948775420442838991310915249099682697586346616093763186183412...
		

Crossrefs

Formula

Equals limit_{n->oo} A368065(n) / (7^(7*n*(n+1)/2) * ((5-sqrt(21))/2)^(sqrt(21)*n*(n+1)/2) * n^(2*n^2 - 4/3) / exp(3*n^2)).
Showing 1-4 of 4 results.