A080613 Minimal sequence such that Omega(a(m))<=Omega(a(n)) for mA001222 (sum of exponents in prime factorization).

1, 2, 3, 4, 25, 6, 49, 8, 27, 20, 1331, 12, 2197, 28, 45, 16, 83521, 36, 130321, 40, 189, 88, 279841, 24, 625, 104, 81, 56, 707281, 60, 923521, 32, 891, 272, 4375, 72, 69343957, 304, 1053, 80, 115856201, 168, 147008443, 176, 405, 368, 229345007, 48

Offset: 1

Author

Reinhard Zumkeller, Feb 25 2003

Keywords

• nonn

Comments

a(n)=n iff n=2^k or n=3*2^k (A029744); A001222(a(n))=A000523(n).

Formula

a(1) = 1, a(n) = if Omega(n)A020639 (smallest prime factor).