A098385 Ordered factorizations over hook-type prime signatures with exactly three distinct primes (third column of A098348).

13, 44, 132, 368, 976, 2496, 6208, 15104, 36096, 84992, 197632, 454656, 1036288, 2342912, 5259264, 11730944, 26017792, 57409536, 126091264, 275775488, 600834048, 1304428544, 2822766592, 6090129408, 13103005696, 28118614016, 60196651008

Offset: 0

Author

Alford Arnold, Sep 06 2004

Keywords

• easy
• nonn

Comments

a(n) can also be calculated by transforming (3,18,8) applying the binomial transform twice. Cf. A098384.

Examples

			The hook-type least prime signatures with exactly three primes begin 30,60,120,...; therefore sequence begins A002033(30,60,120,...) = 13,44,132,...
		

Links

• James Rayman, Table of n, a(n) for n = 0..2000

Crossrefs

Cf. A002033, A098348, A098384.

Programs

Python

def a(n): return 2**n * (n**2 + 8*n + 13) # James Rayman, Mar 27 2021

Formula

a(n) = 2^n * (n^2 + 8*n + 13). - James Rayman, Mar 27 2021

Extensions

More terms from James Rayman, Mar 27 2021