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A080532 Number of nucleons in longest known radioactive decay series ending with Lead 209, reversed. 5
209, 209, 209, 213, 217, 221, 225, 225, 229, 233, 233, 237, 237, 241, 245, 249, 253, 257, 261, 265, 269, 273 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
The numbers are all == 1 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
FORMULA
a(n)=A080536(n)+A080540(n).
CROSSREFS
Sequence in context: A209300 A003740 A303688 * A153442 A159274 A330206
KEYWORD
nonn,hard
AUTHOR
Ralf Stephan, Feb 20 2003
STATUS
approved

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Last modified May 29 18:36 EDT 2024. Contains 372952 sequences. (Running on oeis4.)