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A230852
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Smallest k<3*2^n such that 3*2^n+k is the smallest of four consecutive primes in arithmetic progression or 0 if no solution.
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3
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0, 0, 0, 0, 0, 59, 0, 0, 205, 229, 167, 353, 1595, 4459, 6407, 6215, 14995, 4559, 4697, 11399, 365, 10199, 19327, 39103, 3185, 13649, 15787, 2693, 21455, 24929, 32209, 30509, 13421, 5389, 36947, 12869, 27277, 38389, 973, 69199, 58835, 165629, 52597, 25463, 17923, 38629, 90263, 17153, 48143, 2171, 1255
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OFFSET
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1,6
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COMMENTS
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Conjecture: if n>8 there is always a solution.
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LINKS
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EXAMPLE
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3*2^6+59=251, and 251, 257, 263, 269 are four consecutive primes in arithmetic progression 6 so a(6)=59.
3*2^9+205=1741, and 1741, 1747, 1753, 1759 are four consecutive primes in arithmetic progression 6 so a(9)=205.
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PROG
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(PARI) cpap4(p)=my(q=nextprime(p+1), g=q-p); nextprime(q+1)-q==g&&nextprime(p+2*g+1)==p+3*g
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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