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.

A343864 Decimal expansion of 12*sqrt(3)/(3+sqrt(5)).

Original entry on oeis.org

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

Views

Author

Wesley Ivan Hurt, May 03 2021

Keywords

Comments

Surface area to volume ratio of an icosahedron with unit side length.

Links

Crossrefs

Cf. A343745.

Programs

  • Mathematica
    RealDigits[12 Sqrt[3]/(3 + Sqrt[5]), 10, 100] // Flatten

Formula

3.9695072294976449862092208742056524...

A343829 Distinct values of gcd(B(2*j), B(2*j+2)) in the order of their appearance, where B(k) = A027641(k).

Original entry on oeis.org

1, 587, 491, 37, 103, 59, 131, 67, 283, 101, 691, 157, 617, 593, 149, 233, 683, 271, 263, 307, 577, 653, 379, 257, 467, 293, 21719, 541, 1721, 631, 3617, 409, 839, 463
Offset: 1

Views

Author

Robert G. Wilson v, Apr 30 2021

Keywords

Comments

Conjecture: all terms greater than 1 are irregular primes (A000928) or a product of irregular primes.

Crossrefs

Cf. A000928, A027641, A343745.

Programs

  • Mathematica
    a = Numerator@ BernoulliB@ 2; b = Numerator@ BernoulliB@ 4; k = 6; lst = {}; While[k < 75001, a = b; b = Numerator@ BernoulliB@ k; g = GCD[a, b]; If[ !MemberQ[ lst, g], AppendTo[lst, g]]; k += 2]; lst
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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