A109686 Smallest number beginning with the digits of n that has exactly n prime factors (counted with multiplicity).

11, 21, 30, 40, 500, 64, 704, 864, 9072, 1024, 11264, 120832, 133120, 143360, 1505280, 163840, 1720320, 18063360, 1966080, 20054016, 210567168, 22020096, 231211008, 243269632, 254803968, 2600468480, 2751463424, 28028436480, 2952790016, 30576476160, 31138512896, 32614907904, 330225942528

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

a(5)=500 since 500 has prime factorization 500=2*2*5*5*5 (5 factors) and begins with 5 and is the smallest such number.

Crossrefs

Sequence in context: A195100 A125164 A101223 * A077522 A308232 A049201

Adjacent sequences: A109683 A109684 A109685 * A109687 A109688 A109689

Keyword

base,nonn

Author

Erich Friedman, Aug 07 2005

Extensions

a(24)-a(33) from Donovan Johnson, Apr 27 2008

Status

approved