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 11-14 of 14 results.

A165578 Partial sums of A011627.

Original entry on oeis.org

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

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Author

Antti Karttunen, Sep 22 2009

Keywords

Comments

Period 229.

Crossrefs

Programs

Formula

a(n) = -(a(n-1) + a(n-2) + ... + a(n-228)) = a(n-229). - Charles R Greathouse IV, Feb 11 2013

A165581 Legendre symbol (n,524287).

Original entry on oeis.org

0, 1, 1, -1, 1, -1, -1, -1, 1, 1, -1, -1, -1, 1, -1, 1, 1, -1, 1, -1, -1, 1, -1, -1, -1, 1, 1, -1, -1, 1, 1, 1, 1, 1, -1, 1, 1, 1, -1, -1, -1, 1, 1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, -1, 1, -1, 1, 1, 1, 1, -1, 1, -1, 1, -1, 1, 1, -1, 1, 1, 1, 1, 1, 1, -1, -1, 1, -1, 1, -1, 1, 1, -1
Offset: 0

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Author

Antti Karttunen, Sep 22 2009

Keywords

Comments

524287 is the 7th Mersenne prime, A000668(7) = 2^19 - 1.
Periodic with period 524287. - Charles R Greathouse IV, Aug 06 2012

Crossrefs

Partial sums: A165582.

Programs

A226519 Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} Legendre(i,prime(n)).

Original entry on oeis.org

1, 1, 0, 1, 0, -1, 0, 1, 2, 1, 2, 1, 0, 1, 0, 1, 2, 3, 2, 1, 0, 1, 0, 1, 0, 1, 2, 1, 0, -1, -2, -1, 0, -1, 0, 1, 2, 1, 2, 1, 0, -1, 0, 1, 0, -1, -2, -1, -2, -1, 0, 1, 0, -1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 1, 0, -1, 0, 1, 0, 1, 2, 3, 4, 3, 4, 3, 4, 5, 4, 3, 4, 5, 4, 3, 4, 3, 4, 3, 2, 1, 0
Offset: 1

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Author

N. J. A. Sloane, Jun 19 2013

Keywords

Comments

Strictly speaking, the symbol in the definition is the Legendre-Jacobi-Kronecker symbol, since the Legendre symbol is defined only for odd primes.

Examples

			Triangle begins:
  1;
  1, 0;
  1, 0, -1, 0;
  1, 2,  1, 2, 1, 0;
  1, 0,  1, 2, 3, 2,  1,  0,  1, 0;
  1, 0,  1, 2, 1, 0, -1, -2, -1, 0, -1,  0;
  1, 2,  1, 2, 1, 0, -1,  0,  1, 0, -1, -2, -1, -2, -1, 0;
  ...
		

References

  • József Beck, Inevitable randomness in discrete mathematics, University Lecture Series, 49. American Mathematical Society, Providence, RI, 2009. xii+250 pp. ISBN: 978-0-8218-4756-5; MR2543141 (2010m:60026). See page 23.

Crossrefs

A variant of A226518, which is the main entry for this triangle.

Programs

  • Magma
    A226519:= func< n,k | n eq 1 select k else  (&+[JacobiSymbol(j, NthPrime(n)): j in [0..k]]) >;
    [A226519(n,k) : k in [1..NthPrime(n)-1], n in [1..15]]; // G. C. Greubel, Oct 05 2024
    
  • Maple
    with(numtheory);
    T:=(n,k)->add(legendre(i,ithprime(n)),i=1..k);
    f:=n->[seq(T(n,k),k=1..ithprime(n)-1)];
    [seq(f(n),n=1..15)];
  • Mathematica
    Table[P = Prime[n]; Table[JacobiSymbol[k,P], {k,P-1}]//Accumulate, {n,15}]// Flatten (* G. C. Greubel, Oct 05 2024 *)
  • SageMath
    def A226519(n,k): return k if n==1 else sum(jacobi_symbol(j, nth_prime(n)) for j in range(k+1))
    flatten([[A226519(n,k) for k in range(1,nth_prime(n))] for n in range(1,16)]) # G. C. Greubel, Oct 05 2024

A165577 Partial sums of A011626.

Original entry on oeis.org

0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 3, 4, 3, 2, 1, 2, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 3, 4, 5, 6, 5, 4, 5, 6, 5, 6, 5, 4, 3, 4, 3, 2, 3, 4, 3, 2, 3, 4, 5, 4, 3, 2, 3, 2, 1, 0, 1, 0, 1, 0, -1, 0, 1, 2, 3, 2, 1, 0, 1, 2, 3, 2, 3, 4, 5, 6, 7, 8, 9, 8, 9, 10, 9, 10, 11, 10, 11, 10, 11, 12, 11, 12, 11, 10, 9
Offset: 0

Views

Author

Antti Karttunen, Sep 22 2009

Keywords

Comments

Period 227.

Crossrefs

Previous Showing 11-14 of 14 results.