1,1

4!=(4!/2-1)+(4!/2+1), 5!=(5!/2-1)+(5!/2+1), 27!=(27!/2-107)+(27!/2+107),

77!=(77!/2-397)+(77!/2+397) and 102!=(102!/2-103)+(102!/2+103).

102 is the only known number n such that two numbers n!/2-(n+1) and n!/2+(n+1)

are consecutive primes. There is no further term up to 700.

No other terms below 1000. [From Max Alekseyev (maxale(AT)gmail.com), Feb 14 2009]

Carlos Rivera Sum of k primes = Product of k integers

(77!/2-397) and (77!/2+397) are consecutive primes so 77 is in the sequence.

Get["NumberTheory`NumberTheoryFunctions`"];

Do[If[PreviousPrime[n!/2]+NextPrime[n!/2]==n!, Print[n]], {n, 700}]

Cf. A153430.

Sequence in context: A144053 A084465 A056200 this_sequence A092659 A002352 A042647

Adjacent sequences: A153426 A153427 A153428 this_sequence A153430 A153431 A153432

more,nonn

Farideh Firoozbakht (mymontain(AT)yahoo.com), Feb 07 2009