A164023 -id:A164023 - cp's OEIS frontend

A001748 a(n) = 3 * prime(n).

6, 9, 15, 21, 33, 39, 51, 57, 69, 87, 93, 111, 123, 129, 141, 159, 177, 183, 201, 213, 219, 237, 249, 267, 291, 303, 309, 321, 327, 339, 381, 393, 411, 417, 447, 453, 471, 489, 501, 519, 537, 543, 573, 579, 591, 597, 633, 669, 681, 687, 699, 717, 723, 753

Offset: 1

N. J. A. Sloane

Semiprimes divisible by 3. - Jianing Song, Oct 02 2022

Paolo P. Lava, Table of n, a(n) for n = 1..20000
Eric Weisstein's World of Mathematics, Skeleton

Subsequence of A001358.

Cf. A000040, A100484, A253046, A164023, A164024, A179545, A253046.

a001748 = (* 3) . a000040  -- Reinhard Zumkeller, Dec 26 2014

[3*p: p in PrimesUpTo(300)]; // Vincenzo Librandi, Mar 26 2014

Prime[Range[22]]*3 (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)

3*primes(22) \\ Charles R Greathouse IV, May 19 2011

A164023(a(n)) = A164024(a(n)) = A000040(n). - Reinhard Zumkeller, Aug 09 2009
a(n) = 3*A000040(n). - Omar E. Pol, Jan 31 2012
A253046(a(n)) < a(n). - Reinhard Zumkeller, Dec 26 2014

A164024 Largest of smallest parts in partitions of n into exactly three primes.

Original entry on oeis.org

2, 2, 2, 3, 2, 3, 2, 3, 2, 5, 2, 5, 2, 5, 2, 7, 2, 5, 2, 7, 2, 7, 2, 7, 2, 7, 2, 11, 2, 11, 2, 11, 2, 13, 2, 11, 2, 13, 2, 13, 2, 13, 2, 13, 2, 17, 2, 17, 2, 17, 2, 19, 2, 17, 2, 19, 2, 17, 2, 19, 2, 19, 2, 23, 2, 19, 2, 19, 2, 23, 2, 23, 2, 19, 2, 23, 2, 23, 2, 23, 2, 29, 2, 29, 2, 29, 2, 31, 2

Offset: 6

Reinhard Zumkeller, Aug 08 2009

nonn

a(even) = 2.

a(n)<=n/3; equality occurs at n= 3*prime, and then a(n) are new records 2,3,5,7,11,.. - Zak Seidov, Aug 09 2009

			a(16) = max{min(2,3,11),min(2,7,7)} = max{2,2} = 2;
a(17) = max{min(2,2,13),min(3,3,11),min(3,7,7),min(5,5,7)} = max{2,2,3,5} = 5.

Index entries for sequences related to Goldbach conjecture

A164023, A068307.

cp's OEIS Frontend

A001748 a(n) = 3 * prime(n).

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