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A067066 Number of Gnutella users reachable with given connections and hops. 0
1, 2, 1, 3, 4, 1, 4, 9, 6, 1, 5, 16, 21, 8, 1, 6, 25, 52, 45, 10, 1, 7, 36, 105, 160, 93, 12, 1, 8, 49, 186, 425, 484, 189, 14, 1, 9, 64, 301, 936, 1705, 1456, 381, 16, 1, 10, 81, 456, 1813, 4686, 6825, 4372, 765, 18, 1, 11, 100, 657, 3200, 10885, 23436, 27305, 13120, 1533, 20, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..66.

Jordan Ritter, Why Gnutella Can't Scale. No, Really.

FORMULA

T(n,k) = n * Sum_{i=0..k-1} (n-1)^i.

EXAMPLE

     1      1      1      1      1      1      1 ...

     2      4      6      8     10     12     14 ...

     3      9     21     45     93    189    381 ...

     4     16     52    160    484   1456   4372 ...

     5     25    105    425   1705   6825  27305 ...

     6     36    186    936   4686  23436 117186 ...

     7     49    301   1813  10885  65317 391909 ...

CROSSREFS

Cf. A104881.

Sequence in context: A093375 A103283 A104698 * A210219 A125103 A171275

Adjacent sequences:  A067063 A067064 A067065 * A067067 A067068 A067069

KEYWORD

nonn,tabl,easy

AUTHOR

Michael Somos, Feb 17 2002

EXTENSIONS

Offset corrected, R. J. Mathar, May 22 2016

STATUS

approved

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Last modified June 24 14:30 EDT 2019. Contains 324325 sequences. (Running on oeis4.)