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.

A024453 a(n) = [ (3rd elementary symmetric function of P(n))/(first elementary symmetric function of P(n)) ], where P(n) = {first n+2 primes}.

Original entry on oeis.org

3, 14, 48, 124, 279, 543, 981, 1710, 2758, 4329, 6519, 9365, 13088, 18023, 24448, 32237, 42031, 53897, 67765, 84548, 104253, 127677, 155845, 188299, 224778, 266201, 312202, 363845, 426136, 495751, 574268, 660165, 758682, 865898, 984968, 1116797
Offset: 1

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Programs

  • Maple
    N:= 100: # to get the first N terms
    P:= [seq(ithprime(i),i=1..N+2)]:
    E1:= ListTools:-PartialSums(P):
    E2:= ListTools:-PartialSums([0,seq(P[i]*E1[i-1],i=2..N+2)]):
    E3:= ListTools:-PartialSums([0,seq(P[i]*E2[i-1],i=2..N+2)]):
    seq(floor(E3[n]/E1[n]),n=3..N+2); # Robert Israel, May 01 2019

Formula

a(n) = floor(A024448(n)/A007504(n+2)). - Robert Israel, May 01 2019