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 A066567 #24 Sep 18 2024 15:04:37 %S A066567 2,8,13,63,91,100,128,185,215,221,337,400,448,456,549,551,559,681,900, %T A066567 1024,1089,1151,1185,1215,1221,1327,1348,1437,1600,1651,1897,2025, %U A066567 2112,2191,2196,2209,2293,2304,2392,2401,2448,2500,2539,2544,2551,2596,2601 %N A066567 Numbers that when incremented by the product of their digits produce a square. %H A066567 Harry J. Smith, <a href="/A066567/b066567.txt">Table of n, a(n) for n = 1..1000</a> %e A066567 63 belongs to this sequence as 63 + 6*3 = 81 = 9^2. %t A066567 f[n_] := n + Apply[ Times, IntegerDigits[n]]; Select[ Range[ 2500], IntegerQ[ Sqrt[ f[ # ]]] & ] %t A066567 Select[Range[3000],IntegerQ[Sqrt[#+Times@@IntegerDigits[#]]]&] (* _Harvey P. Dale_, Sep 15 2024 *) %o A066567 (PARI) isok(k) = issquare(k+vecprod(digits(k))); \\ _Harry J. Smith_, Mar 05 2010 %Y A066567 Cf. A000290, A066564, A230099. %K A066567 base,nonn %O A066567 1,1 %A A066567 _Amarnath Murthy_, Dec 18 2001 %E A066567 More terms from _Robert G. Wilson v_, Dec 22 2001 %E A066567 Offset changed from 0 to 1 by _Harry J. Smith_, Mar 05 2010