A124581
Abundant cubes.
Original entry on oeis.org
216, 1000, 1728, 2744, 5832, 8000, 10648, 13824, 17576, 21952, 27000, 46656, 64000, 74088, 85184, 110592, 125000, 140608, 157464, 175616, 216000, 287496, 314432, 343000, 373248, 438976, 474552, 512000, 592704, 681472, 729000, 778688, 884736
Offset: 1
216 is in the sequence because 216=6^3 and the sum of the proper divisors of 216 is 108+72+54+...+3+2+1 > 216.
Cf.
A111029 = magic products of 3 X 3 multiplicative magic squares.
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isA005101 := proc(n) if numtheory[sigma](n) > 2*n then RETURN(true) ; else RETURN(false) ; fi ; end : for n from 1 to 120 do if isA005101(n^3) then printf("%d,",n^3) ; fi ; od ; # R. J. Mathar, Jan 07 2007
with(numtheory): a:=proc(n) if sigma(n^3)>2*n^3 then n^3 else fi end: seq(a(n),n=1..110); # Emeric Deutsch, Jan 10 2007
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Select[Range[100]^3, DivisorSigma[1, #] > 2# &] (* Amiram Eldar, Aug 14 2019 *)
A113026
Magic products of 6 X 6 multiplicative magic squares.
Original entry on oeis.org
25945920, 26611200, 28828800, 29937600, 31449600, 33264000, 33929280, 34594560, 34927200, 35380800, 37255680, 37699200, 37920960, 38918880, 39312000, 39916800, 40098240, 40360320, 41126400, 41277600, 41912640, 42134400, 43243200, 44029440, 44352000, 44553600, 44815680, 44906400, 45239040, 45904320
Offset: 1
Christian Boyer (cboyer(AT)club-internet.fr), Jan 03 2006
Here is a 6 X 6 multiplicative magic square:
1 22 39 54 28 20
12 65 18 8 3 77
30 27 14 52 11 4
42 16 6 33 15 13
26 21 44 5 24 9
66 2 10 7 78 36
The magic product of each row, column or diagonal is 25945920.
A113027
Magic products of 7 X 7 multiplicative magic squares.
Original entry on oeis.org
3632428800, 4151347200, 4410806400, 4540536000, 4670265600, 4750099200, 4843238400, 4929724800, 5145940800, 5189184000, 5292967680, 5308934400, 5428684800, 5448643200, 5613753600, 5708102400, 5751345600, 5811886080, 5837832000, 5881075200, 5915669760, 5937624000, 5967561600, 6054048000, 6067353600, 6107270400, 6175128960, 6227020800, 6274195200, 6333465600
Offset: 1
Christian Boyer (cboyer(AT)club-internet.fr), Jan 03 2006
Here is a 7 X 7 multiplicative magic square:
11 27 1 64 60 49 65
52 35 36 55 2 12 42
28 48 39 10 70 33 3
25 44 56 9 18 26 14
6 5 77 78 84 8 30
63 4 40 21 13 20 66
24 91 15 7 22 45 16
The magic product of each row, column or diagonal is 3632428800.
A114060
Smallest magic product for an n X n multiplicative magic square.
Original entry on oeis.org
216, 5040, 302400, 25945920, 3632428800, 670442572800, 140792940288000
Offset: 3
Showing 1-4 of 4 results.
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