A024522 a(n) = 2nd elementary symmetric function of {1, prime(1), prime(2), ..., prime(n-1)}, where prime(0) = 1.

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

Links

Table of n, a(n) for n=2..37.

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: A173580 A062256 A378493 * A144841 A203245 A121244

Adjacent sequences: A024519 A024520 A024521 * A024523 A024524 A024525

Keyword

nonn

Author

Clark Kimberling

Status

approved