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A024448
a(n) = 3rd elementary symmetric function of the first n+2 primes.
7
30, 247, 1358, 5102, 16186, 41817, 98190, 220628, 441410, 852887, 1551568, 2631642, 4293186, 6866813, 10757450, 16151192, 23873746, 34440605, 48249066, 66877582, 91117898, 122953643, 165196270, 218615372, 284119458, 364962773, 462059210, 579605426, 732954370
OFFSET
1,1
LINKS
MAPLE
SymmPolyn := proc(L::list, n::integer)
local c, a, sel;
a :=0 ;
sel := combinat[choose](nops(L), n) ;
for c in sel do
a := a+mul(L[e], e=c) ;
end do:
a;
end proc:
A024448 := proc(n)
[seq(ithprime(k), k=1..n+2)] ;
SymmPolyn(%, 3) ;
end proc: # R. J. Mathar, Sep 23 2016
# second Maple program:
b:= proc(n) option remember; convert(series(`if`(n=0, 1,
b(n-1)*(ithprime(n)*x+1)), x, 4), polynom)
end:
a:= n-> coeff(b(n+2), x, 3):
seq(a(n), n=1..30); # Alois P. Heinz, Sep 06 2019
MATHEMATICA
b[n_] := b[n] = If[n == 0, 1, b[n - 1] (Prime[n] x + 1)];
a[n_] := SeriesCoefficient[b[n + 2], {x, 0, 3}];
a /@ Range[30] (* Jean-François Alcover, Feb 03 2020, after Alois P. Heinz *)
CROSSREFS
Sequence in context: A042752 A334981 A230703 * A125367 A126525 A230615
KEYWORD
nonn
STATUS
approved