A076205 - OEIS

%I #20 Sep 08 2022 08:45:07

%S 360,523,654,941,1020,1047,1064,1136,1188,1213,1264,1280,1343,1355,

%T 1445,1477,1515,1526,1530,1533,1582,1623,1652,1693,1842,1900,1960,

%U 2018,2039,2129,2208,2280,2309,2332,2406,2413,2440,2499,2539,2622,2633,2650,2657

%N Numbers n such that 30*n+{1,7,11,13,17,19,23,29} are all composite.

%D H. S. M. Coxeter and W. O. J. Moser, Generators and Relations for Discrete Groups, 4th ed., Springer-Verlag, NY, reprinted 1984, p. 141.

%H Klaus Brockhaus, <a href="/A076205/b076205.txt">Table of n, a(n) for n = 1..6829</a> (terms < 100000)

%t Select[Range[3000],AllTrue[30#+{1,7,11,13,17,19,23,29},CompositeQ]&] (* _Harvey P. Dale_, Jan 06 2022 *)

%o (PARI) {cav(mx)= local(wp=[1,7,11,13,17,19,23,29],v=[],i,j,m); for(k=1,mx, i=k*30;j=1;m=1;while(m&&(j<9),m=!isprime(i+wp[j]);j+=1);if(m,v=concat(v,k))); return(v)}

%o (Magma) [ n: n in [0..3000] | forall{ q: q in [1, 7, 11, 13, 17, 19, 23, 29] | not IsPrime(30*n+q) } ]; // _Klaus Brockhaus_, Feb 24 2011

%Y Cf. A005776, A007775, A100418-A100423.

%K easy,nonn

%O 1,1

%A _Donald S. McDonald_, Nov 02 2002

%E More terms from Ferenc Adorjan (fadorjan(AT)freemail.hu), Nov 19 2004

%E Edited by _Don Reble_, Nov 17 2005

%E Edited by _N. J. A. Sloane_, Sep 14 2008 at the suggestion of _R. J. Mathar_