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A165144 Number of semiprimes between two primes squared. 2
1, 5, 7, 22, 15, 33, 23, 49, 88, 35, 114, 79, 48, 100, 148, 189, 57, 201, 139, 78, 230, 158, 269, 370, 192, 102, 215, 112, 211, 803, 259, 390, 150, 666, 147, 430, 471, 317, 485, 506, 152, 869, 168, 364, 184, 1144, 1213, 404, 206, 433, 613, 217, 1134, 702, 720, 712 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..56.

FORMULA

a(n) = A217019(n) - 1. - Flávio V. Fernandes, Nov 19 2020

MAPLE

A165144 := proc(n) a := 0 ; for k from ithprime(n)^2+1 to ithprime(n+1)^2-1 do if numtheory[bigomega](k) = 2 then a := a+1 ; fi ; end do ; a ; end proc: seq(A165144(n), n=1..80) ; # R. J. Mathar, Jan 30 2010

CROSSREFS

Cf. A001248 (primes squared), A001358 (semiprimes), A217019.

Sequence in context: A030735 A303189 A162462 * A084164 A036498 A350193

Adjacent sequences:  A165141 A165142 A165143 * A165145 A165146 A165147

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Sep 05 2009

EXTENSIONS

a(7) corrected and terms beyond a(7) added by R. J. Mathar, Jan 30 2010

STATUS

approved

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Last modified September 28 17:45 EDT 2022. Contains 357080 sequences. (Running on oeis4.)