The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A063777 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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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).
(history; published version)

#6 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

PROG

(PARI) t(n) = (sigma(n) - n)*omega(n); { 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))) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 31 2009]

KEYWORD

nonn,new

nonn

#5 by N. J. A. Sloane at Fri Jan 09 03:00:00 EST 2009

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearlszevi_35711(AT)cableoneyahoo.netcom), Aug 16 2001

#4 by N. J. A. Sloane at Wed Sep 22 03:00:00 EDT 2004

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearls(AT)4grccableone.comnet), Aug 16 2001

#3 by N. J. A. Sloane at Sat Jun 12 03:00:00 EDT 2004

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearls(AT)kskc4grc.netcom), Aug 16 2001

#2 by N. J. A. Sloane at Thu Feb 19 03:00:00 EST 2004

PROG

(PARI) a=0; t(n) = (sigma(n)-n)*omega(n); for(n=1, 10^7, x=t(n^2); if(issquare(x), b=x; if(b>a, a=b; print(n))))

KEYWORD

nonn,new

nonn

#1 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003

NAME

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).

DATA

1, 3, 49, 114, 290, 1266, 3026, 4587, 8642, 14949, 21504, 47976, 74535, 79922, 102818, 112960, 172658, 280226, 632018, 662546, 693794, 791858, 969698, 1516322, 1758962, 2128898, 2184626, 2298242, 2414738, 2594882, 2718578

OFFSET

1,2

EXAMPLE

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

PROG

(PARI) a=0; t(n) = (sigma(n)-n)*omega(n); for(n=1, 10^7, x=t(n^2); if(issquare(x), b=x; if(b>a, a=b; print(n))))

CROSSREFS

Cf. A001065, A001221.

KEYWORD

nonn

AUTHOR

Jason Earls (jcearls(AT)kskc.net), Aug 16 2001

STATUS

approved