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A080530 Number of nucleons in longest known radioactive decay series ending with Lead 207 ("actinium series"), reversed. +0
6
207, 207, 211, 211, 215, 215, 219, 223, 227, 227, 231, 235, 239, 243, 247, 251, 255, 259, 263, 267, 271 (list; graph; listen)
OFFSET

0,1

COMMENT

The numbers are all equivalent to 3 mod 4. The sequence was submitted reversed, as it is open in the past. It is unknown if reversed decay series are finite (the "island of stability" hypothesis).

LINKS

C. Heilman, The Pictorial Periodic Table

FORMULA

a(n)=A080534(n)+A080538(n).

CROSSREFS

Cf. A080529, A080531, A080532.

Sequence in context: A113490 A054007 A133149 this_sequence A045069 A052093 A103477

Adjacent sequences: A080527 A080528 A080529 this_sequence A080531 A080532 A080533

KEYWORD

nonn,hard

AUTHOR

Ralf Stephan (ralf(AT)ark.in-berlin.de), Feb 20 2003

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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