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.

A023567 Convolution of A023531 and primes.

Original entry on oeis.org

0, 2, 3, 5, 9, 14, 18, 24, 32, 39, 51, 57, 71, 85, 94, 108, 124, 142, 152, 176, 193, 205, 229, 249, 271, 295, 315, 336, 364, 386, 408, 444, 468, 490, 526, 561, 583, 617, 663, 681, 717, 745, 781, 831, 862, 894, 924, 968, 1006, 1050, 1100, 1138, 1174
Offset: 1

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Programs

  • Maple
    Primes:= select(isprime, [2,seq(i,i=3..1000,2)]):
    seq(add(Primes[n - i*(i+3)/2],i=1..floor((sqrt(1+8*n)-3)/2)), n=2..nops(Primes)); # Robert Israel, Dec 28 2015
  • PARI
    vector(20,x,c=0;j=x;t=3;while(j>1,c+=prime(j-1);j-=t;t+=1);c)

Formula

a(n) = Sum_{i=0..n-1} A023531(n-i)*p(i+1) where p(i) is the i-th prime.

Extensions

Corrected (term 781 was missing) by Jeremy Gardiner, Feb 05 2014