Primes p with pi(p), pi(2*p), pi(3*p) and pi(4*p) all prime, where pi(x) denotes the number of primes not exceeding x.

A240604

Primes p with pi(p), pi(2*p), pi(3*p) and pi(4*p) all prime, where pi(x) denotes the number of primes not exceeding x.

Terms

    a(0) =10909a(1) =67247a(2) =185869a(3) =408379a(4) =511111a(5) =1297061a(6) =1730461a(7) =1732333a(8) =2135347a(9) =2266079a(10) =2316203a(11) =2978917a(12) =3477737a(13) =4337257a(14) =4495739a(15) =4691849a(16) =6108461a(17) =6407971a(18) =6591163a(19) =7462589a(20) =7909507a(21) =8165039a(22) =8298337a(23) =8948509a(24) =11144083a(25) =11961373a(26) =15019049a(27) =16074059a(28) =16732561a(29) =19316263

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