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 A014342 Convolution of primes with themselves. 12
 4, 12, 29, 58, 111, 188, 305, 462, 679, 968, 1337, 1806, 2391, 3104, 3953, 4978, 6175, 7568, 9185, 11030, 13143, 15516, 18177, 21150, 24471, 28152, 32197, 36678, 41543, 46828, 52621, 58874, 65659, 73000, 80949, 89462, 98631, 108396, 118869, 130102 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(n) = Sum_{i=1..n} p(i) * p(n+1-i), where p(i) is the i-th prime. G.f.: (b(x)^2)/x, where b(x) is the g.f. of A000040. - Mario C. Enriquez, Dec 13 2016 EXAMPLE a(2)=12 because a(2) = p(1)*p(2)+p(2)*p(1) = 2*3+3*2 = 12. MAPLE A014342:=n->add(ithprime(i)*ithprime(n+1-i), i=1..n): seq(A014342(n), n=1..50); # Wesley Ivan Hurt, Dec 14 2016 MATHEMATICA Table[Sum[Prime[i] Prime[n + 1 - i], {i, n}], {n, 40}] (* Michael De Vlieger, Dec 13 2016 *) Table[With[{p=Prime[Range[n]]}, ListConvolve[p, p]], {n, 40}]//Flatten (* Harvey P. Dale, May 03 2018 *) PROG (PARI) {m=40; u=vector(m, x, prime(x)); for(n=1, m, v=vecextract(u, concat("1..", n)); w=vector(n, x, u[n+1-x]); print1(v*w~, ", "))} \\ Klaus Brockhaus, Apr 28 2004 (Haskell) a014342 n = a014342_list !! (n-1) a014342_list= f (tail a000040_list) [head a000040_list] 1 where    f (p:ps) qs k = sum (zipWith (*) qs \$ reverse qs) :                    f ps (p : qs) (k + 1) -- Reinhard Zumkeller, Apr 07 2014, Mar 08 2012 (MAGMA) [&+[NthPrime(n-i+1)*NthPrime(i): i in [1..n]]: n in [1..40]]; // Bruno Berselli, Apr 12 2016 CROSSREFS Cf. A000040, A023626, A024697, A025129, A209403. Sequence in context: A091521 A050898 A009845 * A086274 A174121 A128563 Adjacent sequences:  A014339 A014340 A014341 * A014343 A014344 A014345 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Felix Goldberg (felixg(AT)tx.technion.ac.il), Feb 01 2001 STATUS approved

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Last modified August 20 21:50 EDT 2018. Contains 313928 sequences. (Running on oeis4.)