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.

A362069 Numbers k such that k+digitsum(k^2) is a square.

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%I A362069 #37 May 28 2023 08:45:40
%S A362069 0,17,62,71,117,125,197,206,296,297,305,413,414,557,558,692,702,711,
%T A362069 863,864,872,873,1062,1070,1071,1268,1493,1502,1727,1736,1737,1745,
%U A362069 1998,2006,2267,2276,2285,2564,2565,2573,2879,2888,2889,3221,3222
%N A362069 Numbers k such that k+digitsum(k^2) is a square.
%C A362069 Conjecture: there are infinitely many pairs of consecutive terms. Example: (296,297); (413,414); (863,864).
%e A362069 k=17 is a term because k^2=289 and 17+2+8+9=36=6^2.
%t A362069 Select[Range[0, 3300], IntegerQ[Sqrt[# + Plus @@ IntegerDigits[#^2]]] &] (* _Amiram Eldar_, May 18 2023 *)
%o A362069 (PARI) isok(k)=issquare(k+sumdigits(k^2))
%Y A362069 Cf. A004159, A066564.
%K A362069 nonn,easy,base
%O A362069 1,2
%A A362069 _Alexandru Petrescu_, May 17 2023