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A242254 Numbers k such that the k-th prime is primes-greedy 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See A242252 for the definitions of greedy sum and summability.  a(n) is the index for the n-th primes-greedy 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 .... primes-greedy 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

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Last modified December 12 12:30 EST 2019. Contains 329958 sequences. (Running on oeis4.)