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A115398 Numbers n such that both n^2+1 and 2^n + 1 are semiprimes. 0
3, 5, 11, 12, 19, 28, 61, 64, 79, 92, 101, 104, 199, 356, 596, 692 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A085722 and A092559.

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

11 is OK because 11^2+1=122=2*61 (semiprime) and 2^11+1=2049=3*683 (semiprime).

CROSSREFS

Cf. A085722, A092559.

Sequence in context: A006538 A066281 A072063 * A014597 A130603 A069977

Adjacent sequences:  A115395 A115396 A115397 * A115399 A115400 A115401

KEYWORD

more,nonn

AUTHOR

Zak Seidov, Mar 08 2006

STATUS

approved

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Last modified June 19 01:40 EDT 2013. Contains 226359 sequences.