

A242254


Numbers k such that the kth prime is primesgreedy summable, as defined at A242252.


5



3, 4, 6, 8, 11, 14, 18, 21, 27, 29, 34, 35, 36, 42, 43, 44, 46, 50, 53, 54, 58, 61, 62, 65, 69, 70, 81, 82, 83, 84, 90, 99, 102, 105, 107, 110, 114, 116, 117, 121, 126, 128, 139, 141, 142, 143, 145, 146, 149, 153, 158, 172, 173, 174, 176, 177, 178, 179, 183
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OFFSET

1,1


COMMENTS

See A242252 for the definitions of greedy sum and summability. a(n) is the index for the nth primesgreedy summable prime; those primes are given at A242255.


LINKS

Clark Kimberling, Table of n, a(n) for n = 1..500


EXAMPLE

a(n) ... a(n)th prime .... primesgreedy sum
3 ...... 5 ................ 3 + 2
4 ...... 7 ................ 5 + 2
6 ...... 13 ............... 11 + 2
8 ...... 19 ............... 17 + 2
35 ..... 149 .............. 139 + 7 + 3


MATHEMATICA

z = 200; s = Table[Prime[n], {n, 1, z}]; t = Table[{s[[n]], #, Total[#] == s[[n]]} &[ DeleteCases[Differences[FoldList[If[#1  #2 >= 0, #1  #2, #1] &, s[[n]], Reverse[Select[s, # < s[[n]] &]]]], 0]], {n, z}]; r[n_] := s[[n]]  Total[t[[n]][[2]]]; tr = Table[r[n], {n, 2, z}] (* A242252 *)
c = Table[Length[t[[n]][[2]]], {n, 2, z}] (* A242253 *)
f = 1 + Flatten[Position[tr, 0]] (* A242254 *)
Prime[f] (* A242255 *)
f1 = Prime[Complement[Range[Max[f]], f]] (* A242256 *)
(* Peter J. C. Moses, May 06 2014 *)


CROSSREFS

Cf. A242252, A242253, A242255, A242256, A241833, A000040.
Sequence in context: A079401 A156040 A325172 * A107770 A067054 A039893
Adjacent sequences: A242251 A242252 A242253 * A242255 A242256 A242257


KEYWORD

nonn,easy


AUTHOR

Clark Kimberling, May 09 2014


STATUS

approved



