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A005242 A self-generating sequence.
(Formerly M0971)
3

%I M0971 #27 Dec 26 2021 21:08:32

%S 1,2,4,5,8,10,12,14,15,16,19,20,21,24,25,27,28,32,33,34,37,38,40,42,

%T 43,44,46,47,48,51,53,54,56,57,58,59,61,62,63,64,66,68,69,72,73,74,77,

%U 79,81,83,84,86,88,89,91,92,94,96,97,98,100

%N A self-generating sequence.

%C Presumably this is the lexicographically earliest sequence of distinct positive numbers with the property that sums of two or three consecutive earlier terms are excluded. - _N. J. A. Sloane_, Jan 07 2021

%D R. K. Guy, Unsolved Problems in Number Theory, E30.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Reinhard Zumkeller, <a href="/A005242/b005242.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeNumberofMeasurement.html">Prime Number of Measurement.</a>

%o (Haskell)

%o import Data.List ((\\))

%o a005242 n = a005242_list !! (n-1)

%o a005242_list = f [1..] 0 0 where

%o f (x:xs) y z = x : f (xs \\ [x + y, x + y + z]) x y

%o -- _Reinhard Zumkeller_, May 23 2013

%Y Cf. A002048, A033627.

%K nonn

%O 1,2

%A _N. J. A. Sloane_

%E More terms from _Jud McCranie_, Feb 15 1997

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Last modified March 29 09:14 EDT 2024. Contains 371268 sequences. (Running on oeis4.)