A128303 Indices of squares (of semiprimes) in the 4-almost primes.

1, 3, 8, 12, 24, 29, 59, 66, 90, 97, 162, 172, 187, 224, 234, 335, 385, 412, 489, 531, 551, 630, 692, 791, 921, 997, 1128, 1223, 1256, 1285, 1420, 1484, 1518, 1549, 1937, 2146, 2315, 2441, 2483, 2556, 2606, 2651, 2915, 3124, 3175, 3542, 3587, 3645, 3751, 3800

Offset

1,2

Comments

A014613(a(n)) = A074985(n) = A001358(n)^2.

Links

Table of n, a(n) for n=1..50.

Example

a(5) = 24 as 196=14^2=semiprime(5)^2, the 5th square in the 4-almost primes, is the 24th 4-almost prime.

Crossrefs

Cf. A128302, A014613, A074985, A001358, A128304.

Sequence in context: A209934 A007434 A379717 * A123906 A065970 A326890

Adjacent sequences: A128300 A128301 A128302 * A128304 A128305 A128306

Keyword

nonn

Author

Rick L. Shepherd, Mar 04 2007

Status

approved