A395530 a(n) is the least number of 5-smooth numbers that add up to n.

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 1, 2, 2, 2, 2, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1

Offset

1,7

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

N:= 100: # for a(1)..a(N)
S:= {1}:
for p in [2, 3, 5] do
  S:= S union map(proc(t) local i; seq(p^i*t, i=1..floor(log[p](N/t))) end proc, S)
od:
f:= proc(n) option remember; if member(n, S) then 1 else min(map(k -> f(n-k) + 1, select(`<`, S, n))) fi end proc:
map(f, [$1..N]); # Robert Israel, Apr 28 2026

Crossrefs

Cf. A051037, A237442.

Sequence in context: A352517 A347981 A065081 * A366643 A212185 A270928

Adjacent sequences: A395527 A395528 A395529 * A395531 A395532 A395533

Keyword

nonn

Author

Zhicheng Wei, Apr 27 2026

Status

approved