A090787 - OEIS

A090787

Number of ways to get n by evaluating 1 (+ or *) 2 (+ or *) 3 ... (+ or *) m for some positive integer m. No parentheses are allowed and the usual order of precedence (* before +) is followed.

1, 1, 1, 0, 1, 2, 1, 0, 1, 2, 1, 0, 0, 2, 3, 1, 0, 0, 1, 2, 2, 1, 0, 1, 3, 3, 2, 2, 2, 1, 1, 3, 2, 0, 2, 3, 1, 1, 3, 4, 2, 1, 1, 2, 3, 3, 4, 2, 1, 2, 2, 1, 0, 3, 6, 5, 3, 1, 3, 3, 2, 3, 2, 3, 5, 5, 3, 4, 6, 4, 2, 1, 2, 4, 4, 5, 6, 7, 5, 2, 2, 2, 3, 5, 6, 4, 2, 6, 7, 4, 4, 4, 2, 2, 7, 9, 6, 3, 4, 7, 6, 4, 2, 4, 8

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

COMMENTS

Sequence suggested by Leroy Quet in SeqFan memo 3500 dated Feb 02 2004, where the first fifteen terms were given.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..5000

Rémy Sigrist, C program

EXAMPLE

a(55)=6, since 55 = 1+2+3+4+5+6+7+8+9+10 = 1*2*3+4+5+6+7+8+9+10 = 1*2+3+4*5+6+7+8+9 = 1+2+3+4+5*6+7+8 = 1*2*3+4+5*6+7+8 = 1+2*3*4+5*6.

PROG

CROSSREFS