A014351 Four-fold exponential convolution of primes with themselves (divided by 8).

2, 12, 74, 460, 2861, 17722, 109037, 665020, 4014521, 23954342, 141123193, 820074040, 4697137637, 26504081542, 147300078809, 806343223508, 4349380581953, 23130233881414, 121379963732665, 629130600591920, 3224186845616653, 16354295398317790, 82187373706636505

Offset

0,1

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Maple

b:= proc(n, k) option remember; `if`(k=1, ithprime(n+1), add(
      b(j, floor(k/2))*b(n-j, ceil(k/2))*binomial(n, j), j=0..n))
    end:
a:= n-> b(n, 4)/8:
seq(a(n), n=0..30);  # Alois P. Heinz, Jun 07 2018

Mathematica

b[n_, k_] := b[n, k] = If[k==1, Prime[n+1], Sum[b[j, Floor[k/2]] b[n-j, Ceiling[k/2]] Binomial[n, j], {j, 0, n}]];
a[n_] := b[n, 4]/8;
a /@ Range[0, 30] (* Jean-François Alcover, Nov 16 2020, after Alois P. Heinz *)

Crossrefs

Cf. A014352.

Sequence in context: A020049 A020004 A078469 * A378404 A360318 A074616

Adjacent sequences: A014348 A014349 A014350 * A014352 A014353 A014354

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved