A154891 - OEIS

%I #6 Jan 29 2019 01:52:13

%S 1,2,4,9,12,21,24,30,42,45,57,60,75,84,90,105,135,150,165,195,210,255,

%T 315,330,390,420,525,630,735,825,840,945,1050,1155,1365,1575,1680,

%U 1785,1995,2100,2145,2205,2310,2625,2730,3045,3255,3465,3990

%N Where records occurs in A154804.

%p A008578 := proc(n) RETURN( n=1 or isprime(n) ) ; end : A154804 := proc(n) local a,d; a := 0 ; for d from 1 to n-1 do if A008578(n-d) and A008578(n+d) then a := a+1; fi; od: a ; end: a804 := [seq(A154804(n),n=1..4000)] ; r := RECORDS(a804)[2] ; # _R. J. Mathar_, Mar 14 2009

%Y Cf. A008578, A154804, A154720, A154721, A154799.

%K nonn

%O 1,2

%A _Omar E. Pol_, Feb 01 2009

%E More terms from _R. J. Mathar_, Mar 14 2009