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A066615 Numbers which are not the sum of two or three distinct primes. +0
1
1, 2, 3, 4, 6, 11, 17 (list; graph; listen)
OFFSET

1,2

COMMENT

Probably finite!

An outgrouth of Goldbach's conjecture. "[I]n a letter to L. Euler (1742), C. F. Goldbach [asserted] that 'every odd number greater than 6 is equal to the sum of three primes.' Euler replied that Boldbach's conjecture was equivalent to the statement that every even number equal to or greater than 4 is equal to the sum of two primes. Because proving the second implies the first, but not the converse, most attention has been focused on the second representation. However, whether the statement is true for all even integers is still unsettled. Nevertheless, it is supported by existing evidence. A Russian mathematician, I. M. Vinogradov, proved that all large odd integers are the sum of three primes. Surprisingly, his techniques involve extremely subtle use of the theory of complex variables; no one has been able to extend them in order to solve Goldbach's conjecture." Andrews.

"Every number greater than 17 is the sum of 3 integers greater than 1 which are relatively prime in pairs." - Wells.

REFERENCES

George E. Andrews, "Number Theory," Dover Publ. Inc., NY, 1994, page 111.

Calvin C. Clawson, "Mathematical Mysteries, the beauty and magic of numbers," Perseus Books, Cambridge, MA, 1996, Chapter 12, Pages 236-257.

Mark Herkommer, "Number Theory, A Programmer's Guide," McGraw-Hill, NY, 1999, pages 359-362.

Ivan Niven, Herbert S. Zuckerman and Hugh L. Montgomery, "An Introduction to The Theory of Numbers," Fifth Edition, John Wiley & Sons, Inc. NY, 1991, page 2.

W. Sierpinski, '250 Problems in Elementary Number Theory,' no. 48.

David Wells, "The Penguin Dictionary of Curious and Interesting Numbers," Revised Edition, Penguin Books, London, 1997, page 76.

LINKS

Index entries for sequences related to Goldbach conjecture

MATHEMATICA

a = Table[ Prime[n], {n, 1, 100}]; b = {0}; Do[ b = Append[b, a[[i]] + a[[j]]], {j, 2, 100}, {i, 1, j - 1}]; Union[b]; c = {0}; Do[ c = Append[c, a[[i]] + a[[j]] + a[[k]]], {k, 3, 100}, {j, 2, k - 1}, {i, 1, j - 1}]; Union[c]; Complement[ Table[n, {n, 1, 541} ], Union[b, c]]

CROSSREFS

Cf. A001031.

Sequence in context: A050886 A079310 A116853 this_sequence A133951 A111124 A117308

Adjacent sequences: A066612 A066613 A066614 this_sequence A066616 A066617 A066618

KEYWORD

fini,nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Dec 24 2001

EXTENSIONS

Entry revised by Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 27 2001

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.


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