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A063777 t(n^2) is a square and sets a new record for such squares, where t(n) = (sigma(n)-n)*omega(n); or t(n)= A001065(n)*A001221(n). 0

%I

%S 1,3,49,114,290,1266,3026,4587,8642,14949,21504,47976,74535,79922,

%T 102818,112960,172658,280226,632018,662546,693794,791858,969698,

%U 1516322,1758962,2128898,2184626,2298242,2414738,2594882,2718578

%N t(n^2) is a square and sets a new record for such squares, where t(n) = (sigma(n)-n)*omega(n); or t(n)= A001065(n)*A001221(n).

%e t(49^2) = 400, a square.

%o (PARI) a=0; t(n) = (sigma(n)-n)*omega(n);

%o for(n=1,10^7,x=t(n^2); if(issquare(x),b=x; if(b>a,a=b; print1(n, ", "))))

%o (PARI) t(n) = (sigma(n) - n)*omega(n);

%o { n=0; a=-1; for (m=1, 10^9, if(issquare(b=t(m^2)), if(b>a, a=b; write("b063777.txt", n++, " ", m); if (n==31, break))) ) } \\ _Harry J. Smith_, Aug 31 2009

%Y Cf. A001065, A001221.

%K nonn

%O 1,2

%A _Jason Earls_, Aug 16 2001

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Last modified September 27 08:39 EDT 2021. Contains 347689 sequences. (Running on oeis4.)