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A136799 Last term in a sequence of at least 3 consecutive composite integers. 4
10, 16, 22, 28, 36, 40, 46, 52, 58, 66, 70, 78, 82, 88, 96, 100, 106, 112, 126, 130, 136, 148, 156, 162, 166, 172, 178, 190, 196, 210, 222, 226, 232, 238, 250, 256, 262, 268, 276, 280, 292, 306, 310, 316, 330, 336, 346, 352, 358, 366, 372, 378, 383, 388, 396 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The BASIC program below is useful in testing Grimm's Conjecture, subject of Carlos Rivera's Puzzle 430

Use the program with lines 30 and 70 enabled in the first run and then disabled with lines 31 and 71 enabled in the second run.

LINKS

Carlos Rivera, Puzzle 430, Grimm's Conjecture, Prime puzzles and problems connection.

FORMULA

a(n) = A025584(n+2) -1 . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 24 2008

EXAMPLE

a(1)=10 because 10 is the last term in a run of three composites beginning with 8 and ending with 10 (8,9,10).

PROG

UBASIC: 10 'puzzle 430 (gap finder) 20 N=1 30 A=1:S=sqrt(N):print N; 31 'A=1:S=N\2:print N; 40 B=N\A 50 if B*A=N and B=prmdiv(B) then print B; 60 A=A+1 70 if A<=sqrt(N) then 40 71 'if A<=N\2 then 40 80 C=C+1:print C 90 N=N+1: if N=prmdiv(N) then C=0:print:stop:goto 90:else 30

CROSSREFS

Cf. A136798, A136800, A136801.

Sequence in context: A129848 A083118 A004261 * A055987 A187397 A152138

Adjacent sequences:  A136796 A136797 A136798 * A136800 A136801 A136802

KEYWORD

easy,nonn

AUTHOR

Enoch Haga (Enokh(AT)comcast.net), Jan 21 2008

EXTENSIONS

Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 27 2009

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Last modified February 15 13:57 EST 2012. Contains 205810 sequences.