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.

A036263 Second differences of primes.

Original entry on oeis.org

1, 0, 2, -2, 2, -2, 2, 2, -4, 4, -2, -2, 2, 2, 0, -4, 4, -2, -2, 4, -2, 2, 2, -4, -2, 2, -2, 2, 10, -10, 2, -4, 8, -8, 4, 0, -2, 2, 0, -4, 8, -8, 2, -2, 10, 0, -8, -2, 2, 2, -4, 8, -4, 0, 0, -4, 4, -2, -2, 8, 4, -10, -2, 2, 10, -8, 4, -8, 2, 2, 2, -2, 0, -2, 2, 2, -4, 4, 2, -8, 8, -8, 4, -2, 2, 2, -4, -2, 2, 8, -4
Offset: 1

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Author

Keywords

Examples

			a(3) = 5 + 11 - 2*7 = 16 - 14 = 2.
		

Crossrefs

For records see A293154, A293155.

Programs

  • Haskell
    a036263 n = a036263_list !! (n-1)
    a036263_list = zipWith (-) (tail a001223_list) a001223_list
    -- Reinhard Zumkeller, Oct 29 2011
    
  • Maple
    A036263:=n->ithprime(n) + ithprime(n+2) - 2*ithprime(n+1); seq(A036263(n), n=1..100); # Wesley Ivan Hurt, Apr 01 2014
  • Mathematica
    Table[Prime[n - 1] + Prime[n + 1] - 2*Prime[n], {n, 2, 105}]
    Differences[Prime[Range[100]], 2] (* Harvey P. Dale, Oct 14 2012 *)
  • PARI
    for(n=2,100,print1(prime(n+2)-2*prime(n+1)+prime(n)","))
    
  • Python
    from sympy import prime
    def A036263(n): return prime(n)-(prime(n+1)<<1)+prime(n+2) # Chai Wah Wu, Sep 28 2024

Formula

a(A064113(n)) = 0. - Reinhard Zumkeller, Jan 20 2012
a(n) = prime(n) + prime(n+2) - 2*prime(n+1). - Thomas Ordowski, Jul 21 2012
Conjecture: |a(1)| + |a(2)| + ... + |a(n)| ~ prime(n). - Thomas Ordowski, Jul 21 2012
a(n) = A001223(n+1) - A001223(n). - R. J. Mathar, Sep 19 2013
Sum_{i = 1..n - 1} a(i) = A046933(n), n >= 1. - Daniel Forgues, Apr 15 2014
Sum_{i = 2..n - 1} a(i) = prime(n + 1) - prime(n) - 2; Sum_{i = 2..n - 1} a(i) = 0 whenever prime(n) is a lesser of twin primes. - Hamdi Murat Yildirim, Jun 24 2014

A293155 Indices of record high values in A036263.

Original entry on oeis.org

1, 3, 10, 29, 98, 216, 1182, 1830, 2224, 2809, 3384, 17005, 23282, 30801, 31544, 40932, 103519, 104070, 149688, 887312, 1094420, 1319944, 2850173, 6957875, 10655461, 20684331, 24805378, 27180064, 33772761, 64955633, 82618491, 90422071, 95831002, 112228682
Offset: 1

Views

Author

N. J. A. Sloane, Oct 10 2017

Keywords

Crossrefs

Programs

  • Maple
    arec := 0 ;
    for i from 1 do
        a := A036263(i) ;
        if a > arec then
            arec := a;
            printf("%d,\n",i) ;
        end if;
    end do: # R. J. Mathar, Oct 13 2017
  • PARI
    See Links section.

Extensions

More terms from Rémy Sigrist, Mar 17 2019
Showing 1-2 of 2 results.