login
A024522
a(n) = 2nd elementary symmetric function of {1, prime(1), prime(2), ..., prime(n-1)}, where prime(0) = 1.
0
2, 11, 41, 118, 316, 693, 1407, 2528, 4322, 7251, 11281, 17238, 25356, 35633, 48887, 66324, 88862, 115763, 149397, 189796, 236516, 292843, 358579, 436454, 529962, 637123, 756809, 892164, 1041712, 1209065, 1411503, 1636954, 1890678, 2167149, 2484221, 2828048
OFFSET
2,1
MAPLE
b:= proc(n) option remember; convert(series(`if`(n=0, 1, b(n-1)*
(`if`(n=1, 1, ithprime(n-1))*x+1)), x, 3), polynom)
end:
a:= n-> coeff(b(n), x, 2):
seq(a(n), n=2..40); # Alois P. Heinz, Sep 08 2019
MATHEMATICA
b[n_] := b[n] = Series[If[n == 0, 1, b[n - 1]*(If[n == 1, 1, Prime[n - 1]]*x + 1)], {x, 0, 3}] // Normal;
a[n_] := Coefficient[b[n], x, 2];
Table[a[n], {n, 2, 40}] (* Jean-François Alcover, Dec 26 2022, after Alois P. Heinz *)
CROSSREFS
Cf. A000040.
Sequence in context: A066593 A173580 A062256 * A144841 A203245 A121244
KEYWORD
nonn
STATUS
approved