A074329 n-th highly composite number equals a(n)-th composite number.

0, 0, 1, 2, 6, 14, 24, 32, 42, 89, 138, 187, 287, 591, 693, 1054, 1416, 2151, 4364, 6600, 8842, 13354, 17879, 22418, 24697, 40653, 45227, 49811, 75040, 100357, 151121, 202000, 252981, 304025, 457506, 508744, 611307, 662636, 996722, 1331409

Offset

1,4

Comments

Since 1 is taken to be the first highly composite number and the 2nd highly composite is the prime 2, so first 2 terms here were taken to be zero. Definition of A002182 is not precise enough.

Links

Table of n, a(n) for n=1..40.

Formula

a(n)=A002182(n)-A000720[A002182(n)]-1; A002182(m)=A002808[a(m)].

Example

3rd term is 4, the first composite number; the 6th highly composite number is 24, the 14th composite number.

Mathematica

t[x_] := A002182[x]; Table[Part[t, w]-PrimePi[Part[t, w]]-1, {w, 1, Length[t]}]

Crossrefs

Cf. A002182, A002808, A000720.

Sequence in context: A307643 A239877 A032386 * A109592 A238410 A256482

Adjacent sequences: A074326 A074327 A074328 * A074330 A074331 A074332

Keyword

nonn

Author

Labos Elemer, Aug 21 2002

Status

approved