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.

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A143853 Primes p that divide the sum of their remainders modulo all smaller composites (=A233131(p)).

Original entry on oeis.org

2, 3, 23, 53, 613, 490537
Offset: 1

Views

Author

Neil Fernandez, Sep 03 2008

Keywords

Comments

The prime elements of A233344.

Examples

			Composites smaller than 23 are 4,6,8,9,10,12,14,15,16,18,20,21 and 22. 23 is congruent to 3,5,7,5,3,11,9,8,7,5,3 and 2 modulo these numbers respectively. The sum of these residues is 69. This is a multiple of 23, so 23 is in the sequence.

Crossrefs

Cf. A143851

Extensions

490537 from Max Alekseyev, Sep 15 2009
Term 2 prepended by Max Alekseyev, Dec 07 2013

A233344 Numbers k that divide the sum of their remainders modulo all smaller composites (=A233131(k)).

Original entry on oeis.org

1, 2, 3, 4, 23, 53, 374, 613, 225460, 490537, 1748155, 3167982, 9266618, 12543856, 12589961, 27359852, 3418801560, 8824909730, 72988555402
Offset: 1

Views

Author

Max Alekseyev, Dec 07 2013

Keywords

Comments

The prime terms are given by A143853.

Crossrefs

Cf. A065132, A143853, A233131.

Programs

  • PARI
    s=0; pp=0; for(n=2,10^8, p=factor(n)[,1]; s += (n-2) - pp - sigma(n) +  sum(i=1,#p,p[i]) + if(!ispseudoprime(n),n,pp++;0) + 1; if(s%n==0,print1(n,", ")) )
Showing 1-2 of 2 results.

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