A151744 Primes which are the sum of two, three, four and five consecutive composite numbers.
17783, 25057, 47303, 48383, 49297, 76343, 89783, 205703, 412343, 516457, 704183, 754417, 790703, 938183, 1105343, 1110743, 1279583, 1563503, 1632817, 1744583, 1890743, 1903103, 2062943, 2276303, 2714617, 2802383, 2812897, 2932703
Offset: 1
Keywords
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..100
Programs
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Mathematica
CompositeNext[n_]:=Module[{k=n+1},While[PrimeQ[k],k++ ];k]; q=9!; lst2={};Do[If[ !PrimeQ[n],c=CompositeNext[n];a2=n+c;If[PrimeQ[a2],AppendTo[lst2,a2]]],{n,q}];lst2; lst3={};Do[If[ !PrimeQ[n],c1=CompositeNext[n];c2=CompositeNext[c1];a3=n+c1+c2;If[PrimeQ[a3],AppendTo[lst3,a3]]],{n,q}];lst3; lst4={};Do[If[ !PrimeQ[n],c1=CompositeNext[n];c2=CompositeNext[c1];c3=CompositeNext[c2];a4=n+c1+c2+c3;If[PrimeQ[a4],AppendTo[lst4,a4]]],{n,q}];lst4; lst5={};Do[If[ !PrimeQ[n],c1=CompositeNext[n];c2=CompositeNext[c1];c3=CompositeNext[c2];c4=CompositeNext[c3];a5=n+c1+c2+c3+c4;If[PrimeQ[a5],AppendTo[lst5,a5]]],{n,q}];lst5; Intersection[lst2,lst3,lst4,lst5] (* Vladimir Joseph Stephan Orlovsky, Jun 17 2009 *) Module[{comps=Select[Range[2*10^6],CompositeQ]},Intersection@@ Table[ Select[ Total/@ Partition[comps,n,1],PrimeQ],{n,2,5}]] (* Harvey P. Dale, Apr 16 2015 *)
Formula
Extensions
Extended beyond a(7) by Klaus Brockhaus, Jun 16 2009
Comments