A073674 Rearrangement of odd numbers such that every partial product + 2 is a prime.
1, 3, 5, 7, 9, 15, 19, 25, 27, 53, 43, 11, 33, 49, 17, 29, 95, 37, 13, 31, 23, 41, 47, 63, 81, 35, 51, 69, 113, 45, 57, 21, 67, 75, 55, 107, 73, 137, 131, 231, 61, 103, 39, 115, 59, 145, 91, 101, 205, 125, 77, 227, 93, 129, 127, 161, 201, 167, 97, 165, 141, 155, 169
Offset: 1
Keywords
Examples
For 1, 3, 5, 7: 1+2 = 3, 1*3+2 = 5, 1*3*5+2 = 17, 1*3*5*7+2 = 107 are primes. - _Daniel Forgues_, Dec 20 2012
Programs
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Mathematica
f[s_List] := Block[{k = 1, p = Times @@ s}, While[ MemberQ[s, k] || !PrimeQ[k*p + 2], k += 2]; Append[s, k]]; Nest[f, {1}, 62] (* Robert G. Wilson v, Dec 24 2012 *)
Extensions
More terms from Sascha Kurz, Feb 01 2003