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.

A135484 a(n) = Sum_{i=1..n} i^prime(i), where prime(i) denotes i-th prime number.

Original entry on oeis.org

1, 9, 252, 16636, 48844761, 13109538777, 232643623525984, 144347831699381856, 8863082467484200477785, 100000008863082467484200477785, 192043424966613562971631041769596
Offset: 1

Views

Author

Ctibor O. Zizka, Feb 07 2008

Keywords

Crossrefs

Partial sums of A062481.

Programs

  • Mathematica
    f[n_] := Sum[i^Prime@i, {i, n}]; Array[f, 12] (* Robert G. Wilson v, Feb 12 2008 *)
    Accumulate[Table[n^Prime[n],{n,15}]] (* Harvey P. Dale, Nov 30 2023 *)
  • PARI
    a(n) = sum(k=1, n, k^prime(k)); \\ Michel Marcus, Oct 15 2016

Extensions

Edited and extended by Robert G. Wilson v, Feb 12 2008

A135485 a(n) = Sum_{i=1..n} prime(i)^(i-1), where prime(i) denotes i-th prime number.

Original entry on oeis.org

1, 4, 29, 372, 15013, 386306, 24523875, 918395614, 79229380895, 14586375356764, 834214662337565, 178751836441797978, 22742242136807984059, 1741006366419098769302, 258407992554086508103671
Offset: 1

Views

Author

Ctibor O. Zizka, Feb 07 2008, Feb 17 2008

Keywords

Comments

The primes in this sequence are 29 = 2^0 + 3^1 + 5^2, 15013 = 2^0 + 3^1 + 5^2 + 7^3 + 11^4, 82630...60939 (a 107-digit number) = 2^0 + 3^1 + 5^2 + ... + 211^46, ...

Crossrefs

Partial sums of A093360.

Programs

  • Mathematica
    f[n_] := Sum[Prime[i]^(i - 1), {i, n}]; Array[f, 16] (* Robert G. Wilson v, Feb 12 2008 *)
  • PARI
    a(n) = sum(k=1, n, prime(k)^(k-1)); \\ Michel Marcus, Oct 15 2016

Extensions

Edited and extended by Robert G. Wilson v, Feb 12 2008

A291140 Sum of the n-th powers of the first n primes.

Original entry on oeis.org

2, 13, 160, 3123, 181258, 6732437, 493478344, 24995572327, 2255433009730, 470444892889497, 38714638073629150, 7749166585021832891, 1203906832960860262108, 121893712541593098356317, 17161342484454585041813494
Offset: 1

Views

Author

Vojtech Strnad, Aug 18 2017

Keywords

Examples

			a(3) = 2^3 + 3^3 + 5^3 = 160.
		

Crossrefs

Programs

  • Maple
    f:= n -> add(ithprime(i)^n,i=1..n):
    map(f, [$1..20]); # Robert Israel, Aug 20 2017
  • Mathematica
    Table[Total[Prime[Range@ n]^n], {n, 15}] (* Michael De Vlieger, Aug 19 2017 *)
  • PARI
    a(n) = sum(i=1, n, prime(i)^n) \\ Felix Fröhlich, Aug 18 2017

Formula

a(n) = prime(1)^n + prime(2)^n + ... + prime(n)^n.

A298883 Determinant of n X n matrix whose elements are m(i,j) = prime(i)^j.

Original entry on oeis.org

1, 2, 6, 180, 50400, 958003200, 131514679296000, 1352181326649753600000, 112703642894318944282214400000, 903025586371469323704949549301760000000, 2012769637740033870687308804001121075357286400000000
Offset: 0

Views

Author

Andres Cicuttin, Jan 28 2018

Keywords

Comments

Traces of these matrices are A087480.

Examples

			For n=1:
          |2| = 2, then a(1) = 2.
For n=2:
          |2  4| = 6, then a(2) = 6.
          |3  9|
For n=3:
          |2  4   8| = 180, then a(3) = 180.
          |3  9  27|
          |5 25 125|
		

Crossrefs

Programs

  • Maple
    with(LinearAlgebra):
    a:= n-> Determinant(Matrix(n, (i,j)-> ithprime(i)^j)):
    seq(a(n), n=0..12);  # Alois P. Heinz, Jan 28 2018
    # Alternative:
    f:= proc(n) local P;
    P:= [seq(ithprime(i),i=1..n)];
    convert(P,`*`)*mul(mul(P[j]-P[i],j=i+1..n),i=1..n-1)
    end proc:
    map(f, [$0..20]); # Robert Israel, Jan 29 2018
  • Mathematica
    a[n_]:=Table[Prime[i]^j,{i,1,n},{j,1,n}];
    Table[Det[a[n]],{n,1,10}]
  • PARI
    a(n) = matdet(matrix(n, n, i, j, prime(i)^j)); \\ Michel Marcus, Jan 28 2018

Formula

a(n) = Product_{1<=i<=n} prime(i) * Product_{1<=iRobert Israel, Jan 29 2018

A179056 Numbers k such that prime(1)^1 + prime(2)^2 + ... + prime(k)^k is prime.

Original entry on oeis.org

1, 2, 8, 6402
Offset: 1

Views

Author

Farideh Firoozbakht, Jun 27 2010

Keywords

Comments

The number corresponding to k=6402 is a probable prime. There is no further term up to 9435.
There is no further term up to 12600. - Michael S. Branicky, Mar 22 2023

Examples

			prime(1)^1 + prime(2)^2 + ... + prime(8)^8 = 17398892111 is prime, so 8 is in the sequence.
		

Crossrefs

Cf. A087480.

Programs

  • Mathematica
    Select[Range[1, 100], PrimeQ[Sum[Prime[i]^i, {i, 1, #}]] &] (* Julien Kluge, Dec 03 2016 *)
Showing 1-5 of 5 results.