A005242 A self-generating sequence.

1, 2, 4, 5, 8, 10, 12, 14, 15, 16, 19, 20, 21, 24, 25, 27, 28, 32, 33, 34, 37, 38, 40, 42, 43, 44, 46, 47, 48, 51, 53, 54, 56, 57, 58, 59, 61, 62, 63, 64, 66, 68, 69, 72, 73, 74, 77, 79, 81, 83, 84, 86, 88, 89, 91, 92, 94, 96, 97, 98, 100

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Comments

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

References

• R. K. Guy, Unsolved Problems in Number Theory, E30.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Prime Number of Measurement.

Crossrefs

Cf. A002048, A033627.

Programs

Haskell

import Data.List ((\\))
a005242 n = a005242_list !! (n-1)
a005242_list = f [1..] 0 0 where
   f (x:xs) y z = x : f (xs \\ [x + y, x + y + z]) x y
-- Reinhard Zumkeller, May 23 2013

Extensions

More terms from Jud McCranie, Feb 15 1997