A093456 -id:A093456 - cp's OEIS frontend

A093455 a(n) = floor(A093456(n+1)/A093456(n)).

1, 24, 30, 3, 48, 2145, 5, 3, 8643, 279, 5, 341, 387, 592, 70045, 0, 113091, 961, 5, 915, 1237, 1276, 1555, 1508, 1682, 2017, 5, 2001, 5, 546739584, 5, 823445198, 0, 3155, 4, 1561809488, 3898, 5, 2674919308, 0, 2971949246306, 5, 5340, 0, 6194377797, 0

Offset: 1

Amarnath Murthy, Apr 03 2004

1, 2, 3, 5 and 6 are the only n such that A093456(n) divides A093456(n+1).

			a(4) = floor[(12*14*15)/(8*9*10)] = Floor(7/2) = 3.

Cf. A093456.

Edited and extended by David Wasserman, Mar 29 2007

A093457 Product of primes in the range [T(n-1) + 1, T(n - 1) + n], where T(n) is the n-th triangular number.

Original entry on oeis.org

1, 6, 5, 7, 143, 323, 23, 899, 65231, 2491, 3599, 347261, 583573, 1009091, 1317919, 16637, 428448457, 4273697, 5605027, 1445140189, 2445956099, 3368562317, 4927316309, 6454166203, 9473323417, 13508676341, 17347785757, 8989229423381

Offset: 1

Amarnath Murthy, Apr 03 2004

nonn

			a(5) = 11*13 = 143.

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Cf. A093455, A093456.

Do[k = 1; Do[If[PrimeQ[i], k = k*i], {i, Binomial[n, 2] + 1, Binomial[n, 2] + n}]; Print[k], {n, 1, 30}] (* Ryan Propper, Jun 22 2005 *)
Join[{1,6},Table[With[{t=(n(n+1))/2},Times@@Select[Range[t+1,t+n],PrimeQ]],{n,2,30}]]  (* Harvey P. Dale, Jan 18 2025 *)

More terms from Ryan Propper, Jun 22 2005

cp's OEIS Frontend

A093455 a(n) = floor(A093456(n+1)/A093456(n)).

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