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.
%I A061890 #47 Oct 06 2023 14:14:04
%S A061890 100,25633969,212372329,292341604,3672424151449,
%T A061890 219704732167875184222756
%N A061890 Squares that are the sum of initial primes.
%C A061890 The set of squares in A007504. - _Zak Seidov_, Oct 07 2015
%H A061890 G. L. Honaker Jr. and C. Caldwell, <a href="https://t5k.org/curios/page.php?curio_id=179">Prime Curios!: 9</a>
%H A061890 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_009.htm">Problem 9: Sum of first k primes is perfect square</a>, The Prime Puzzles & Problems Connection.
%F A061890 a(n) = A061888(n)^2.
%F A061890 Intersection of A000290 and A007504. - _Zak Seidov_, Oct 08 2015
%e A061890 100 = 10^2 = 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23, so 100 is in the sequence.
%p A061890 N:= 10^7: # to use primes up to N
%p A061890 P:= select(isprime, [2,seq(2*i+1, i=1..floor(N/2))]):
%p A061890 S:= ListTools:-PartialSums(P):
%p A061890 select(issqr,S); # _Robert Israel_, Feb 16 2015
%t A061890 s[n_] := Sum[Prime[i], {i, 1, n}];t := Table[s[n], {n, 20000}];Select[t, IntegerQ[Sqrt[#]] &] (* _Carlos Eduardo Olivieri_, Feb 24 2015 *)
%o A061890 (PARI) lista() = {s = 0; forprime(p=2, ,s += p; if (issquare(s), print1(s, ", ")););} \\ _Michel Marcus_, Mar 10 2015
%Y A061890 Cf. A007504, A033997, A033998, A061888.
%Y A061890 Cf. also A066527, A364691, A366269.
%K A061890 nonn,more
%O A061890 1,1
%A A061890 _David W. Wilson_, May 12 2001
%E A061890 Corrected by _Vladeta Jovovic_, May 21 2001
%E A061890 a(6) from _Giovanni Resta_, May 27 2003
%E A061890 Edited by _Ray Chandler_, Mar 20 2007