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A133395 Terms in A061725 that are of form 3*prime. 0
6, 51, 123, 291, 843, 1371, 1851, 2811, 5331, 6243, 6891, 9411, 18771, 36483, 54291, 63003, 69171, 72363, 73443, 76731, 78963, 128883, 143643, 151323, 187491, 212523, 229443, 271443, 292683, 332931, 361203, 398163, 418611, 458331, 477483, 516963 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

3|p^2+2 for all p except 3 hence 3|A061725(n) for all n except n=2. If p^2+2 is semiprime it is of form 3*prime.

LINKS

Table of n, a(n) for n=1..36.

PROG

(PARI) lista(nn) = {vec = vector(nn, i, prime(i)^2 + 2); pp = select(i->((bigomega(i) == 2) && !(i % 3)), vec); print(pp); } \\ Michel Marcus, Oct 13 2013

CROSSREFS

Cf. A061725 (p^2+2 where p=prime).

Sequence in context: A292818 A173082 A113653 * A341424 A050916 A011790

Adjacent sequences:  A133392 A133393 A133394 * A133396 A133397 A133398

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 22 2007

EXTENSIONS

Typo in Comment corrected by Shai Covo (green355(AT)netvision.net.il), Oct 11 2010

STATUS

approved

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Last modified July 24 18:34 EDT 2021. Contains 346273 sequences. (Running on oeis4.)