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A161958 a(n) = smallest composite number which is the sum of n consecutive composite numbers. 0

%I

%S 4,10,18,27,45,49,63,78,94,112,132,153,175,220,224,250,301,305,335,

%T 396,400,434,469,505,543,582,622,664,708,753,799,847,896,946,1045,

%U 1099,1154,1158,1214,1271,1329,1389,1510,1514,1578,1643,1773,1842,1846,1916,1988

%N a(n) = smallest composite number which is the sum of n consecutive composite numbers.

%e a(7) = 4 + 6 + 8 + 9 + 10 + 12 + 14 = 63.

%o (MAGMA) C:=[ k: k in [4..1000] | not IsPrime(k) ]; find:=function(n) j:=0; repeat j+:=1; s:=&+[ C[i]: i in [j..n+j-1] ]; until not IsPrime(s); return s; end function; [ find(n): n in [1..51] ]; // _Klaus Brockhaus_, Jun 27 2009

%Y Cf. A002808 (composite numbers).

%K nonn

%O 1,1

%A _Claudio Meller_, Jun 22 2009

%E Values through a(51) verified by _Klaus Brockhaus_, Jun 27 2009

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Last modified July 17 08:42 EDT 2019. Contains 325098 sequences. (Running on oeis4.)