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 A203524 a(n) = Product_{2 <= i < j <= n+1} (prime(i) + prime(j)). 5
 1, 8, 960, 3870720, 535088332800, 4746447547269120000, 2251903055463146166681600000, 101133031075657891684280256430080000000, 764075218501479062478490016486870993810227200000000, 510692344365454233151092604262379676645631378616169267200000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Each term divides its successor, as in A203525. It is conjectured that each term is divisible by the corresponding superfactorial, A000178(n); as in A203526. See A093883 for a guide to related sequences. LINKS MAPLE a:= n-> mul(mul(ithprime(i)+ithprime(j), i=2..j-1), j=3..n+1): seq(a(n), n=1..10);  # Alois P. Heinz, Jul 23 2017 MATHEMATICA f[j_] := Prime[j + 1]; z = 17; v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}] d[n_] := Product[(i - 1)!, {i, 1, n}]    (* A000178 *) Table[v[n], {n, 1, z}]                   (* A203524 *) Table[v[n + 1]/(8 v[n]), {n, 1, z - 1}]  (* A203525 *) Table[v[n]/d[n], {n, 1, 20}]             (* A203526 *) CROSSREFS Cf. A000040, A203315, A203525, A203526. Sequence in context: A241875 A024111 A231905 * A331491 A300426 A300688 Adjacent sequences:  A203521 A203522 A203523 * A203525 A203526 A203527 KEYWORD nonn AUTHOR Clark Kimberling, Jan 03 2012 EXTENSIONS Name edited by Alois P. Heinz, Jul 23 2017 STATUS approved

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Last modified December 7 09:15 EST 2021. Contains 349574 sequences. (Running on oeis4.)