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A318487 Even numbers that are not the sum of two lucky-indexed lucky numbers. 2
4, 6, 10, 12, 16, 18, 20, 24, 26, 30, 34, 36, 40, 44, 46, 48, 54, 58, 60, 66, 68, 72, 74, 76, 78, 82, 86, 90, 92, 96, 100, 102, 104, 106, 110, 114, 116, 120, 122, 124, 128, 130, 134, 138, 140, 144, 146, 152, 154, 156, 158, 164, 168, 170, 176, 178, 182, 184 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Conjecture (checked up to 10^7): every even number larger than 199254 is the sum of two lucky-indexed lucky numbers, so this sequence is finite with 1714 terms.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..1714

EXAMPLE

28 is not in this sequence since 28 = 7 + 21 and 7 and 21 are lucky-indexed lucky numbers (A032639).

MATHEMATICA

L = Table[2*i + 1, {i, 0, 150000}]; For[n = 2, n < Length[L], r = L[[n++]]; L = ReplacePart[L, Table[r*i -> Nothing, {i, 1, Length[L]/r}]]]; a = L[[Select[L, # <= Length[L] &]]]; v = Select[Range[2, 300000, 2], IntegerPartitions[#, {2}, a] == {} &]; (* after Jean-Fran├žois Alcover at A000959 and Giovanni Resta at A303403 *)

CROSSREFS

Cf. A000959, A032639, A303403.

Sequence in context: A026411 A020189 A166986 * A047233 A194382 A296655

Adjacent sequences:  A318484 A318485 A318486 * A318488 A318489 A318490

KEYWORD

nonn

AUTHOR

Amiram Eldar, Aug 27 2018

STATUS

approved

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Last modified September 24 17:17 EDT 2021. Contains 347651 sequences. (Running on oeis4.)