cp's OEIS Frontend

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.

A084048 Integers m such that the base-10 digit concatenation 2//m//3//m//5//m...//prime(49)//m//prime(50) is prime.

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%I A084048 #10 Jan 07 2021 13:29:19
%S A084048 96,359,546,1422,1644,1980,2241,3458,3606,4530,4629,5018,5090,5114,
%T A084048 5166,7007,7389,8534,9123,9717,9771,10065,10343,10355,10514,10596,
%U A084048 11307,11361,11531,12401,12759,13707,14810,15185,15290,15614,15728,16038
%N A084048 Integers m such that the base-10 digit concatenation 2//m//3//m//5//m...//prime(49)//m//prime(50) is prime.
%C A084048 This is in the family of sequences fp(j,m)=prime(1)//m//prime(2)//m//prime(3)//...//m//prime(j), of which A032711 = fp(2,m) is a simplest type.
%e A084048 96 is in the sequence because fp(50,k)=2//k//3//k//5//k//7//k//11//k//13...//k//229 fp(50,96)=296396596...22796229 is prime.
%e A084048 fp(50,96) is prime number with 219 digits.
%t A084048 Select[Range[16100],PrimeQ[FromDigits[Flatten[IntegerDigits/@ Riffle[ Prime[ Range[ 50]],#]]]]&] (* _Harvey P. Dale_, Jan 07 2021 *)
%Y A084048 Cf. A083677, A032711.
%K A084048 easy,nonn,base
%O A084048 1,1
%A A084048 _Farideh Firoozbakht_, Jun 19 2003