A139321 First occurrence of n in A068307: least number k such that the number of decomposition of k into the sum of three primes is n.

1, 6, 9, 15, 17, 21, 31, 27, 35, 33, 39, 41, 45, 47, 55, 51, 53, 57, 242, 63, 67, 65, 71, 476, 79, 81, 578, 85, 77, 83, 99, 572, 512, 89, 97, 95, 103, 111, 101, 692, 1040, 632, 115, 107, 782, 129, 121, 113, 902, 141, 119, 842, 992, 125, 133, 147, 1520, 131, 159, 145

Offset

0,2

Comments

Records (differs from A139322): 1, 6, 9, 15, 17, 21, 31, 35, 39, 41, 45, 47, 55, 57, 242, 476, 578, 692, 1040, 1520, 1898, 2162, 2480, 3536, 4004, 4034, 4526, 5456, 5918, 7010, 8804, 9740, 10106, 10262, 10412, 10622, 10772, 10952, 11462, 12362, 12452, 12512, 12560, 12662, 12902, ... .

Links

Robert G. Wilson v and T. D. Noe, Table of n, a(n) for n = 0..2500

Mathematica

f[n_] := Block[{c = 0, lmt = PrimePi@ Floor[n/2], p, q}, Do[p = Prime@ i; q = Prime@ j; r = n - p - q; If[ PrimeQ@ r && r >= p, c++ ], {i, lmt}, {j, i}]; c]; t = Table[0, {1000}]; Do[a = f@n; If[t[[a]] == 0, t[[a]] = n; Print[{a, n}]], {n, 10^6}]

Crossrefs

Cf. A000040, A068307. Records: A139322.

Sequence in context: A316022 A316023 A139322 * A210732 A316024 A316025

Adjacent sequences: A139318 A139319 A139320 * A139322 A139323 A139324

Keyword

nonn

Author

Robert G. Wilson v, Apr 13 2008

Status

approved