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A095750
"Degree" of the Sophie Germain primes (A005384).
0
0, 0, 1, 2, 3, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0
OFFSET
0,4
COMMENTS
This sequence is derived from the special case of Cunningham chains of the first kind where every member of the chain is a Sophie Germain prime.
This sequence can be obtained by subtracting 2 from A074313 and then deleting all negative members. - David Wasserman, Sep 13 2007
LINKS
C. K. Caldwell, Cunningham Chains.
Eric Weisstein's World of Mathematics, Cunningham Chain.
EXAMPLE
Entries 0, 0, 1, 2, 3 correspond to the Sophie Germain primes 2, 3, 5, 11, 23. 5 is degree 1 because 5 = (2 * 2) + 1 and 2 is also a Sophie Germain prime. Similarly, 11 = (5 * 2) + 1, therefore 11 is degree 2. 23 = (11 * 2) + 1, thus 23 is degree 3 and so on.
CROSSREFS
Cf. A005384.
Sequence in context: A292247 A194016 A292256 * A056966 A362363 A037846
KEYWORD
easy,nonn
AUTHOR
Andrew S. Plewe, Jul 09 2004
EXTENSIONS
More terms from David Wasserman, Sep 13 2007
STATUS
approved