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A124283 4-almost primes indexed by primes. 8
24, 36, 54, 60, 90, 104, 136, 150, 189, 225, 232, 294, 308, 328, 344, 375, 441, 459, 488, 510, 516, 550, 570, 621, 676, 708, 714, 738, 748, 776, 852, 860, 884, 910, 999, 1014, 1060, 1096, 1112, 1161, 1197, 1206, 1256, 1274, 1284, 1290, 1356, 1432, 1450, 1482 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes indexed by 4-almost primes = A124282. prime(4almostprime(n)) - 4almostprime(prime(n)) = A124284. Primes indexed by 3-almost primes = A124268. 3-almost primes indexed by primes = A124269. prime(3almostprime(n)) - 3almostprime(prime(n)) = A124270. See also A106349 Primes indexed by semiprimes. See also A106350 Semiprimes indexed by primes. See also A122824 Prime(semiprime(n)) - semiprime(prime(n)). Commutator [A000040,A001358] at n.

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = 4almostprime(prime(n)) = A014613(A000040(n)).

EXAMPLE

a(1) = 4almostprime(prime(1)) = 4almostprime(2) = 24.

a(2) = 4almostprime(prime(2)) = 4almostprime(3) = 36.

a(3) = 4almostprime(prime(3)) = 4almostprime(5) = 54.

CROSSREFS

Cf. A000040, A014613, A114414, A122824, A124269, A124270, A124282, A124284.

Sequence in context: A078347 A187516 A165602 * A143645 A003176 A003138

Adjacent sequences:  A124280 A124281 A124282 * A124284 A124285 A124286

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Oct 24 2006

EXTENSIONS

a(17)-a(50) from Giovanni Resta, Jun 13 2016

STATUS

approved

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Last modified May 11 03:49 EDT 2021. Contains 343784 sequences. (Running on oeis4.)