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%I #11 Jul 10 2019 01:48:25
%S 79,127,203,234,243,255,324,325,326,350,361,402,406,416,430,445,447,
%T 471,490,509,513,527,531,539,548,553,561,564,572,602,604,627,630,631,
%U 633,640,653,654,656,694,695,703,704,715,720,735,783,790,791,812,813,818
%N Numbers n with the property that all four polynomials mentioned in A139414 evaluate at n to composite numbers.
%C The four polynomials considered in A139414 are 1373 - 146*n + 4*n^2, 1459 - 144*n + 4*n^2, 1301 - 142*n + 4*n^2, 1877 - 140*n + 4*n^2. For n=79 these are all composite: 14803, 15047, 15047, 15781.
%C An example of exactly 5 consecutive terms in the sequence: 4688-4692. An example of exactly 7 consecutive terms in the sequence: 14753-14759.
%H Harry J. Smith, <a href="/A155814/b155814.txt">Table of n, a(n) for n = 1..10000</a>
%o (PARI) p1(n)=4*n*n-146*n+1373 p2(n)=4*n*n-144*n+1459 p3(n)=4*n*n-142*n+1301 p4(n)=4*n*n-140*n+1877 { n=0; for (p=0, 45837, a1=p1(p); a2=p2(p); a3=p3(p); a4=p4(p); if (!isprime(a1) && !isprime(a2) && !isprime(a3) && !isprime(a4), n++; a=p; print(n," ",a); write("b155814.txt",n," ",a);) ) } \\ _Harry J. Smith_, Jan 28 2009
%Y Cf. A139414.
%K nonn
%O 1,1
%A _Zak Seidov_, Jan 28 2009
%E Edited by _N. J. A. Sloane_, Jan 29 2009
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