A047870 Smallest number that is not a sum of at most one power of each of the numbers 1 through n.

1, 2, 6, 15, 53, 204, 457, 12199, 110580, 765920, 29631246, 733709898, 22329951066

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Example

a(2)=6 because 6 is the first number that is not of the form 1+2^i, 2^i or 1; a(3)=15 because 15 is smallest number not of form 1^i+2^j+3^k where i,j,k = -infinity or >=0.
The old value for a(11), 436070111, was not correct since 436070111 = 1 + 2^26 + 3^7 + 4^2 + 5^8 + 6^11 + 7^8 + 9^4. - Donovan Johnson, Oct 09 2009

Crossrefs

Cf. A047871.

Sequence in context: A323926 A256982 A372853 * A027287 A192186 A243550

Adjacent sequences: A047867 A047868 A047869 * A047871 A047872 A047873

Keyword

nonn,more,nice

Author

Nathan M. Simpson (ntsimp(AT)concentric.net)

Extensions

Corrected and extended by David W. Wilson

Two more terms from Don Reble, Oct 26 2001

a(11) corrected by Donovan Johnson, Oct 08 2009

a(12) from Donovan Johnson, Jul 22 2010

Status

approved