This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A066749 #18 Jul 28 2025 08:18:57
%S A066749 2,3,7,11,71,127,463,3433,2704157,20058301,17672631901,35345263801,
%T A066749 2104098963721,16123801841551,6892620648693261354601,
%U A066749 51913710643776705684835561,410795449442059149332177041,12738806129490428451365214301,760401738905937245009910944207609329
%N A066749 List of primes p which are equal to a central binomial coefficient C(n,floor(n/2)) plus 1.
%C A066749 The corresponding values of n are in A067366.
%H A066749 Harvey P. Dale, <a href="/A066749/b066749.txt">Table of n, a(n) for n = 1..53</a> (The next term, a(54), has 1244 digits.)
%e A066749 For n=5 the central binomial coefficient is C(5,2)=10. Since 10+1=11 is prime, it is in the sequence.
%t A066749 For[ n=0, True, n++, If[ PrimeQ[ z=Binomial[ n, Floor[ n/2 ] ]+1 ], Print[ z ] ] ]
%t A066749 Select[Table[1+Binomial[n,Floor[n/2]],{n,100}],PrimeQ] (* _Harvey P. Dale_, Nov 24 2018 *)
%o A066749 (MuPAD) for n from 0 to 200 do p := binomial(n,floor(n/2))+1: if isprime(p) then print(p) end_if end_for
%Y A066749 Cf. A001405, A067366.
%K A066749 nonn
%O A066749 1,1
%A A066749 Frank Buss (fb(AT)frank-buss.de), Jan 16 2002
%E A066749 Repetitions removed by _N. J. A. Sloane_, Apr 09 2008
%E A066749 More terms from _Harvey P. Dale_, Nov 24 2018