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.

Previous Showing 11-16 of 16 results.

A368370 AGM transform of triangular numbers.

Original entry on oeis.org

0, 4, 514, 113920, 44084375, 28195584256, 28201577788944, 42039291307622400, 89651019067859485125, 264184676314240000000000, 1044528435971290465713291136, 5403748103160416506028643844096, 35801791315095649217787108688094375
Offset: 1

Views

Author

N. J. A. Sloane, Jan 24 2024

Keywords

Comments

See A368366 for further information.

Crossrefs

Programs

  • Mathematica
    Table[Sum[k*(k+1)/2, {k, 1, n}]^n - n^n*Product[k*(k+1)/2, {k, 1, n}], {n, 1, 12}] (* Vaclav Kotesovec, Jan 24 2024 *)
  • Python
    from math import comb, factorial
    def A368370(n): return comb(n+2,3)**n-(n**n*factorial(n)**2*(n+1)>>n) # Chai Wah Wu, Jan 25 2024

Formula

a(n) ~ (n*(n+1)*(n+2)/6)^n - n^n*n!*(n+1)!/2^n. - Vaclav Kotesovec, Jan 24 2024

A369395 AGM transform of the even positive numbers.

Original entry on oeis.org

0, 4, 432, 61696, 12300000, 3339123264, 1195810789376, 549031054934016, 315439869711260160, 222215334010000000000, 188664842745174745939968, 190234762349632291168321536, 224946256003775354246877765632, 308520390288000443379128425267200, 486093585063330330624000000000000000
Offset: 1

Views

Author

Hugo Pfoertner, Jan 24 2024

Keywords

Comments

See A368366 for the definition of the AGM transform.

Crossrefs

Programs

  • Mathematica
    A369395[n_] := n^n*((n+1)^n - (2*n)!!);
    Array[A369395, 15] (* Paolo Xausa, Jan 29 2024 *)
  • PARI
    a369395(n) = {my(v=vector(n,i,i+i)); vecsum(v)^n - n^n*vecprod(v)};
    
  • Python
    from math import factorial
    def A369395(n): return n**n*((n+1)**n-(factorial(n)<Chai Wah Wu, Jan 25 2024

A369698 AGM transform of positive cubes.

Original entry on oeis.org

0, 49, 40824, 96461056, 571250390625, 7338413252698641, 181953686508203782144, 7957561391610438862503936, 572547082070592542500791107625, 64157961305703333114506988525390625, 10714350425499230222239742740718898118656, 2571996060859292513876561308464753498396819456
Offset: 1

Views

Author

Paolo Xausa, Jan 29 2024

Keywords

Comments

See A368366 for the description of the AGM transform.

Crossrefs

Programs

  • Mathematica
    A369698[n_] := (n*(n+1)/2)^(2*n) - n^n*n!^3; Array[A369698, 15]
  • Python
    from math import factorial
    def A369698(n): return ((n*(n+1))**(m:=n<<1)>>m) - n**n*factorial(n)**3 # Chai Wah Wu, Jan 29 2024

Formula

a(n) = A000537(n)^n - A000312(n)*A000442(n).

A369701 AGM transform of the numbers of partitions (A000041) of the positive numbers.

Original entry on oeis.org

0, 1, 54, 6961, 1233318, 487047961, 290742044714, 347251334512896, 683674076661539256, 2495297738110474036224, 14634026423059969492022144, 156866160296614402006202168641, 2612384850652790986902453089127552, 74149419491027435547521058057290511849, 3283295561194682488327071117265547706288707
Offset: 1

Views

Author

Paolo Xausa, Jan 29 2024

Keywords

Comments

See A368366 for the description of the AGM transform.

Crossrefs

Programs

  • Mathematica
    A369701[n_] := With[{p = PartitionsP[Range[n]]}, Total[p]^n - n^n*Apply[Times, p]];
    Array[A369701, 15]

Formula

a(n) = A026905(n)^n - A000312(n)*A058694(n).

A370223 AGM transform of the positive Fibonacci numbers.

Original entry on oeis.org

0, 0, 10, 865, 155082, 52802560, 40048988817, 71202718146816, 315615332953930528, 3574469013941010577249, 104798469697184132865547168, 7984603919946049180938300030976, 1584983603576817306123611193840098529, 820874582413458038007335015822715588591616
Offset: 1

Views

Author

Paolo Xausa, Feb 13 2024

Keywords

Comments

See A368366 for the description of the AGM transform.

Crossrefs

Programs

  • Mathematica
    A370223[n_] := (Fibonacci[n+2]-1)^n - n^n*Fibonorial[n]; Array[A370223, 15]
  • Python
    from itertools import count, islice
    def A370223_gen(): # generator of terms
        a, b, s, p = 1, 1, 0, 1
        for n in count(1):
            s += a
            p *= a
            yield s**n-n**n*p
            a, b = b, a+b
    A370223_list = list(islice(A370223_gen(),10)) # Chai Wah Wu, Feb 16 2024

Formula

a(n) = A000071(n+2)^n - A000312(n)*A003266(n).

A369393 a(n) = 2^n*(((n + 1)/2)^n - n!).

Original entry on oeis.org

0, 0, 1, 16, 241, 3936, 71569, 1452032, 32724801, 814205440, 22221533401, 661258764288, 21336094568881, 742703018860544, 27764596902369825, 1110071630916222976, 47289995917566900481, 2139290897163297619968, 102449006445196880700841, 5179102933596854288384000, 275667346790825720172556401
Offset: 0

Views

Author

Hugo Pfoertner, Jan 24 2024

Keywords

Crossrefs

Previous Showing 11-16 of 16 results.