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A228185 Number of semiprimes generated from Euler's polynomial x^2 + x + 41 from x = 1 to 10^n. 0
0, 14, 393, 4761, 47938, 456157, 4293575, 40357922 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

a(4) = 4761 because the number of semiprimes generated from Euler's polynomial x^2 + x + 41 from x = 1 to 10^4 are 4761.

MATHEMATICA

a = 0; n = 1; t = {}; Do[If[PrimeOmega[x^2 + x + 41]== 2, a = a + 1]; If[Mod[x, n] == 0, n = n*10; AppendTo[t, a]], {x, 1, 100000000}]; t

nn=8; With[{ep=If[PrimeOmega[#]==2, 1, 0]&/@Table[x^2+x+41, {x, 10^nn}]}, Table[ Total[Take[ep, 10^n]], {n, nn}]] (* Harvey P. Dale, Dec 12 2014 *)

CROSSREFS

Cf. A228123.

Sequence in context: A211421 A097310 A223003 * A041367 A041364 A222904

Adjacent sequences:  A228182 A228183 A228184 * A228186 A228187 A228188

KEYWORD

nonn,less

AUTHOR

Shyam Sunder Gupta, Aug 15 2013

STATUS

approved

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Last modified September 21 15:03 EDT 2021. Contains 347598 sequences. (Running on oeis4.)