A138856 Numbers such that all subsets of {prime(a(1)),...,prime(a(n))} have a different sum.

1, 2, 4, 5, 10, 16, 28, 47, 83, 147, 267, 481, 882, 1621, 2997, 5578, 10428, 19560, 36849, 69649, 131983, 250841, 477992, 912662, 1746404, 3347928, 6429526, 12366247, 23820901, 45947255

Offset

1,2

Comments

see A138000,A138857,A138858.

Links

Table of n, a(n) for n=1..30.

Formula

A138856(n)=primepi(A138000(n))

Prog

(PARI) {s=1; p=0; for( n=1, 20, until( !bitand( s, s>>prime(p++) ), ); s+=s<<prime(p); print1( p, ", "))}

Crossrefs

Cf. A138000-138001, A138857-A138858, A064934.

Sequence in context: A059994 A299492 A253198 * A333188 A018401 A049332

Adjacent sequences: A138853 A138854 A138855 * A138857 A138858 A138859

Keyword

nonn

Author

M. F. Hasler, Apr 10 2008

Extensions

a(22)-a(30) from Donovan Johnson, Oct 03 2009

Status

approved