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Search: id:A138882
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| A138882 |
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Triangle read by rows: row n lists divisors of n-th even superperfect number A061652(n). |
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+0
3
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| 1, 2, 1, 2, 4, 1, 2, 4, 8, 16, 1, 2, 4, 8, 16, 32, 64, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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The number of divisors of n-th even superperfect number is equal to A000043(n), then row n has A000043(n) terms.
The sum of divisors of n-th even superperfect number is equal to n-th Mersenne prime A000668(n), then n-th row sum is equal to A000668(n).
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LINKS
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O. E. Pol, Determinacion geometrica de los numeros primos y perfectos".
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EXAMPLE
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Triangle begins:
1, 2
1, 2, 4
1, 2, 4, 8, 16
1, 2, 4, 8, 16, 32, 64
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096
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..... Mersenne ..............................................
....... prime ...............................................
n ... A000668(n) = Sum of divisors of A061652(n) .............
==============================================================
1 ........ 3 ... = 1+2
2 ........ 7 ... = 1+2+4
3 ....... 31 ... = 1+2+4+8+16
4 ...... 127 ... = 1+2+4+8+16+32+64
5 ..... 8191 ... = 1+2+4+8+16+32+64+128+256+512+1024+2048+4096
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CROSSREFS
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Cf. A000005, A000043, A000203, A000668, A019279, A061652, A133031.
Sequence in context: A131074 A059268 A123937 this_sequence A074634 A152036 A035015
Adjacent sequences: A138879 A138880 A138881 this_sequence A138883 A138884 A138885
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KEYWORD
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nonn,tabf
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AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Apr 11 2008
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