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.

A077022 Values of k such that sum of first k primes squared is divisible by k-th prime.

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%I A077022 #22 Jan 14 2023 08:44:39
%S A077022 1,6,17,11156,16548
%N A077022 Values of k such that sum of first k primes squared is divisible by k-th prime.
%C A077022 Numbers k such that A072004(k) = 0.
%C A077022 a(6) > 10^11. - _Giovanni Resta_, Mar 07 2013
%e A077022 6 is a term because A024450(6)/prime(6) = 29;
%e A077022 17 is a term because A024450(17)/prime(17) = 284;
%e A077022 11156 is a term because A024450(11156)/prime(11156) = 410066261;
%e A077022 16548 is a term because A024450(16548)/prime(16548) = 941945317.
%t A077022 Module[{nn=17000,prs},prs=Accumulate[Prime[Range[nn]]^2];Select[Range[ nn],Divisible[prs[[#]],Prime[#]]&]] (* _Harvey P. Dale_, Nov 23 2013 *)
%Y A077022 Cf. A024450, A072004, A077023.
%K A077022 nonn,more
%O A077022 1,2
%A A077022 _Randy L. Ekl_ and _Zak Seidov_, Oct 17 2002