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 A108190 4-almost primes equal to the sum of two successive semiprimes. 1
 24, 36, 100, 184, 189, 372, 472, 484, 513, 532, 580, 644, 748, 824, 904, 940, 1016, 1029, 1036, 1062, 1068, 1096, 1107, 1164, 1180, 1208, 1225, 1236, 1269, 1284, 1304, 1336, 1340, 1395, 1420, 1430, 1444, 1482, 1508, 1521, 1580, 1593, 1610, 1628, 1666 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 EXAMPLE a(1) = 24 because 2*5 + 2*7 = 10 + 14 = 24 = 2*2*2*3. a(5) = 189 because 2*47 + 5*19 = 94 + 95 = 189 = 3*3*3*7. a(11) = 513 because 2*127 + 7*37 = 254 + 259 = 513 = 3*3*3*19. MATHEMATICA Select[Total/@Partition[Select[Range[2000], PrimeOmega[#]==2&], 2, 1], PrimeOmega[ #] ==4&] (* Harvey P. Dale, Apr 26 2018 *) PROG (PARI) list(lim)=my(u=List(), L=lim\2); forprime(p=2, L\2, forprime(q=2, min(p, L\p), listput(u, p*q))); for(k=L+1, 2*L, if(bigomega(k)==2, listput(u, k); break)); u=Set(u); for(i=2, #u, u[i-1]=u[i]+u[i-1]); if(u[#u]>lim, u[#u]=0); select(k->bigomega(k)==4, u) \\ Charles R Greathouse IV, Feb 05 2017 CROSSREFS Sequence in context: A278474 A327946 A288949 * A185489 A303884 A304616 Adjacent sequences: A108187 A108188 A108189 * A108191 A108192 A108193 KEYWORD easy,nonn AUTHOR Giovanni Teofilatto, Jun 15 2005 EXTENSIONS Corrected and extended by Ray Chandler, Jul 07 2005 STATUS approved

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Last modified August 11 14:50 EDT 2024. Contains 375073 sequences. (Running on oeis4.)