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A014351 Four-fold exponential convolution of primes with themselves (divided by 8). 1

%I

%S 2,12,74,460,2861,17722,109037,665020,4014521,23954342,141123193,

%T 820074040,4697137637,26504081542,147300078809,806343223508,

%U 4349380581953,23130233881414,121379963732665,629130600591920,3224186845616653,16354295398317790,82187373706636505

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

%H Alois P. Heinz, <a href="/A014351/b014351.txt">Table of n, a(n) for n = 0..1000</a>

%p b:= proc(n, k) option remember; `if`(k=1, ithprime(n+1), add(

%p b(j, floor(k/2))*b(n-j, ceil(k/2))*binomial(n, j), j=0..n))

%p end:

%p a:= n-> b(n, 4)/8:

%p seq(a(n), n=0..30); # _Alois P. Heinz_, Jun 07 2018

%t 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}]];

%t a[n_] := b[n, 4]/8;

%t a /@ Range[0, 30] (* _Jean-François Alcover_, Nov 16 2020, after _Alois P. Heinz_ *)

%Y Cf. A014352.

%K nonn

%O 0,1

%A _N. J. A. Sloane_.

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Last modified November 30 06:28 EST 2021. Contains 349419 sequences. (Running on oeis4.)