a(2) = a(3) = 0; for n >= 4, a(n) = largest m such that n-m and n+m are both primes, or -1 if no such m exists.
0, 0, 1, 2, 1, 4, 5, 4, 7, 8, 7, 10, 9, 8, 13, 14, 13, 12, 17, 16, 19, 20, 19, 22, 21, 20, 25
6 seqfan posts
Sun Mar 14 00:13:12 CET 2010 [seqfan] Re: No "-1" value in A047949?
Sun Mar 14 21:50:33 CET 2010 [seqfan] Re: No "-1" value in A047949?
Sun Mar 14 19:29:14 CET 2010 [seqfan] Re: No "-1" value in A047949?
Sun Mar 14 05:11:35 CET 2010 [seqfan] Re: No "-1" value in A047949?
Sun Mar 14 00:28:21 CET 2010 [seqfan] Re: No "-1" value in A047949?
Sat Mar 13 23:38:33 CET 2010 [seqfan] No "-1" value in A047949?
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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