A326930 Height of the smallest stack in a block-stacking sequence.

1, 3, 3, 3, 7, 6, 7, 8, 13, 10, 13, 12, 13, 15, 15, 15, 17, 21, 19, 21, 21, 21, 25, 24, 25, 27, 27, 27, 31, 30, 31, 32, 35, 34, 35, 39, 37, 39, 39, 39, 43, 42, 43, 44, 49, 46, 49, 48, 49, 51, 51, 51, 55, 54, 55, 56, 61, 58, 61, 60, 61, 63, 63, 63, 65, 69, 67, 69, 69, 69, 71, 75

Offset: 1

Author

Christian Perfect, Oct 22 2019

Keywords

• easy
• nonn

Comments

This sequence describes a block-stacking process: at step 1, start with a single stack of height 1. At step n>1, if n is less than or equal to the height of the smallest stack, start a new stack of height n. Otherwise, add n to the height of the smallest stack.

Programs

PARI

seq(n)={my(L=List(), a=vector(n)); for(n=1, #a, if(#L && L[1]Andrew Howroyd, Oct 22 2019

Python

def seq():
    towers = [0]
    for i in range(1, 100):
        towers = sorted(towers)
        if i <= towers[0]:
            towers = [i] + towers
        else:
            towers = [towers[0] + i] + towers[1:]
        yield min(towers)