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 1-5 of 5 results.

A307772 Expansion of e.g.f. Sum_{k>=1} prime(k)*log(1 + x)^k/k!.

Original entry on oeis.org

2, 1, 0, -2, 14, -100, 792, -6984, 68112, -728924, 8498662, -107269546, 1457660932, -21221947564, 329615120330, -5440973779098, 95131744001392, -1756450890029772, 34152285999547328, -697588907138104978, 14934641645024407092, -334433142861340604942, 7818455679081107296154
Offset: 1

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Author

Ilya Gutkovskiy, Apr 27 2019

Keywords

Comments

Inverse Stirling transform of primes.

Crossrefs

Programs

  • Mathematica
    nmax = 23; Rest[CoefficientList[Series[Sum[Prime[k] Log[1 + x]^k/k!, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!]
    Table[Sum[StirlingS1[n, k] Prime[k], {k, 1, n}], {n, 1, 23}]

Formula

a(n) = Sum_{k=1..n} Stirling1(n,k)*prime(k).

A307773 Expansion of e.g.f. Sum_{k>=1} prime(k)*log(1/(1 - x))^k/k!.

Original entry on oeis.org

2, 5, 18, 82, 454, 2960, 22212, 188568, 1786896, 18698116, 214149822, 2664667358, 35796803068, 516387315172, 7961576156330, 130655542040262, 2273957872532176, 41836619073742452, 811316702293124504, 16540499893106494782, 353673865103189710572, 7914396129656344633522
Offset: 1

Views

Author

Ilya Gutkovskiy, Apr 27 2019

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> add(ithprime(k)*abs(Stirling1(n, k)), k=1..n):
    seq(a(n), n=1..30);  # Alois P. Heinz, Apr 27 2019
  • Mathematica
    nmax = 22; Rest[CoefficientList[Series[Sum[Prime[k] Log[1/(1 - x)]^k/k!, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!]
    Table[Sum[Abs[StirlingS1[n, k]] Prime[k], {k, 1, n}], {n, 1, 22}]

Formula

a(n) = Sum_{k=1..n} |Stirling1(n,k)|*prime(k).

A351681 Stirling transform of {1, primes}.

Original entry on oeis.org

1, 3, 10, 38, 163, 774, 4004, 22315, 132836, 838378, 5574797, 38861142, 282951538, 2146361911, 16931303262, 138694760316, 1178400013929, 10373294706788, 94511288422822, 890334527133081, 8663213736312460, 86975649078035438, 899960154388259079, 9586293761594853220
Offset: 1

Views

Author

Ilya Gutkovskiy, May 07 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 24; CoefficientList[Series[Exp[x] - 1 + Sum[Prime[k - 1] (Exp[x] - 1)^k/k!, {k, 2, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest
    Table[Sum[StirlingS2[n, k] If[k == 1, 1, Prime[k - 1]], {k, 1, n}], {n, 1, 24}]

Formula

E.g.f.: exp(x) - 1 + Sum_{k>=2} prime(k-1) * (exp(x) - 1)^k / k!.
a(n) = Sum_{k=1..n} Stirling2(n,k) * A008578(k).

A353406 Stirling transform of odd primes.

Original entry on oeis.org

3, 8, 25, 91, 376, 1715, 8471, 44838, 252903, 1514213, 9590874, 64056173, 449804453, 3312346950, 25521479277, 205300781275, 1720450321356, 14986361037495, 135393159641569, 1266006310597506, 12228936468908781, 121823473948915769, 1249794986354577736
Offset: 1

Views

Author

Ilya Gutkovskiy, May 07 2022

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, m) option remember;
         `if`(n=0, ithprime(m+1), m*b(n-1, m)+b(n-1, m+1))
        end:
    a:= n-> b(n-1, 1):
    seq(a(n), n=1..23);  # Alois P. Heinz, May 13 2022
  • Mathematica
    nmax = 23; CoefficientList[Series[Sum[Prime[k + 1] (Exp[x] - 1)^k/k!, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest
    Table[Sum[StirlingS2[n, k] Prime[k + 1], {k, 1, n}], {n, 1, 23}]

Formula

E.g.f.: Sum_{k>=1} prime(k+1) * (exp(x) - 1)^k / k!.
a(n) = Sum_{k=1..n} Stirling2(n,k) * prime(k+1).

A347041 Stirling transform of pi (A000720).

Original entry on oeis.org

0, 0, 1, 5, 21, 88, 389, 1852, 9525, 52632, 310141, 1936489, 12749204, 88149847, 637769490, 4812457992, 37763509549, 307453610201, 2592851608305, 22626572045811, 204197274002794, 1905132039608335, 18370391387293756, 183001650861913887, 1882207129695280320
Offset: 0

Views

Author

Alois P. Heinz, Aug 13 2021

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, m) option remember; `if`(n=0,
          numtheory[pi](m), m*b(n-1, m)+b(n-1, m+1))
        end:
    a:= n-> b(n, 0):
    seq(a(n), n=0..27);

Formula

G.f.: Sum_{k>=0} pi(k)*x^k / Product_{j=1..k} (1-j*x).
E.g.f.: Sum_{k>=0} pi(k)*(exp(x)-1)^k/k!.
a(n) = Sum_{k=0..n} Stirling2(n,k)*pi(k).
Showing 1-5 of 5 results.