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 A236245 Primes of the form C(2*m, m) + prime(m), where C(2*m, m) = (2*m)!/(m!)^2. 6
 263, 937, 3449, 12889, 2704193, 10400641, 35345263867, 23623985175715118288974865541854103729347, 362048725489728431058442528694228154899210914562190067 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Although the primes in this sequence are very rare, by the conjecture in A236241 there should be infinitely many such primes. See A236242 for a list of known numbers m with C(2*m, m) + prime(m) prime. LINKS Zhi-Wei Sun, Table of n, a(n) for n = 1..25 EXAMPLE a(1) = 263 since C(2*5, 5) + prime(5) = 252 + 11 = 263 is prime, and those C(2*m, m) + prime(m) with 0 < m < 5 are composite. MATHEMATICA s[n_]:=Binomial[2n, n]+Prime[n] a[n_]:=s[A236242(n)] Table[a[n], {n, 1, 40}] CROSSREFS Cf. A000040, A000984, A236241, A236242. Sequence in context: A245877 A142379 A128654 * A343192 A023314 A054802 Adjacent sequences: A236242 A236243 A236244 * A236246 A236247 A236248 KEYWORD nonn AUTHOR Zhi-Wei Sun, Jan 20 2014 STATUS approved

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Last modified June 10 05:41 EDT 2023. Contains 363195 sequences. (Running on oeis4.)