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A067187 Numbers which can be expressed as the sum of two primes in exactly one way. 10
4, 5, 6, 7, 8, 9, 12, 13, 15, 19, 21, 25, 31, 33, 39, 43, 45, 49, 55, 61, 63, 69, 73, 75, 81, 85, 91, 99, 103, 105, 109, 111, 115, 129, 133, 139, 141, 151, 153, 159, 165, 169, 175, 181, 183, 193, 195, 199, 201, 213, 225, 229, 231, 235, 241, 243, 253, 259, 265, 271 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

All primes + 2 are terms of this sequence. Is 12 the last even term? - Frank Ellermann (f-e(AT)hamburg.de), Jan 17, 2002

Comment from Eric Weisstein, Oct 10, 2003: A048974, A052147, A067187 and A088685 are very similar after dropping terms less than 13.

Values of n such that A061358(n)=1. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 03 2006

LINKS

Index entries for sequences related to Goldbach conjecture

EXAMPLE

4 is a term as 4 = 2+2, 15 is a term as 15 = 13+2.

MAPLE

g:=sum(sum(x^(ithprime(i)+ithprime(j)), i=1..j), j=1..80): gser:=series(g, x=0, 280): a:=proc(n) if coeff(gser, x^n)=1 then n else fi end: seq(a(n), n=1..272); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 03 2006

CROSSREFS

Cf. A023036, A067188-A067191, A066722, A045917, A061358.

Subsequence of A014091.

Cf. A061358.

Sequence in context: A016070 A047569 A039062 * A161674 A189481 A123977

Adjacent sequences:  A067184 A067185 A067186 * A067188 A067189 A067190

KEYWORD

nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jan 10 2002

EXTENSIONS

Edited by Frank Ellermann (f-e(AT)hamburg.de), Jan 17, 2002

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Last modified February 17 03:20 EST 2012. Contains 205978 sequences.