A025058 Numbers of form i*j + j*k + k*i, where 1 <=i < j < k, including repetitions.

11, 14, 17, 19, 20, 23, 23, 26, 26, 27, 29, 29, 31, 31, 32, 34, 35, 35, 36, 38, 38, 39, 39, 41, 41, 41, 43, 44, 44, 44, 46, 47, 47, 47, 47, 49, 50, 50, 51, 51, 52, 53, 53, 54, 54, 55, 55, 56, 56, 56, 59, 59, 59, 59, 59, 61, 61, 62, 62, 62, 63, 63, 64, 65, 65

Offset

1,1

Links

Bo Gyu Jeong, Table of n, a(n) for n = 1..2000

Example

11 is in the sequence because 11 = 1*2 + 2*3 + 3*1.
23 appears twice because 23 = 1*3 + 3*5 + 5*1 = 1*2 + 2*7 + 7*1.

Prog

(Python)
def aupto(N):
    alst = []
    for i in range(1, N-1):
        for j in range(i+1, N//i + 1):
            p, s = i*j, i+j
            for k in range(j+1, (N-p)//s + 1):
                alst.append(p + s*k)
    return sorted(alst)
print(aupto(65)) # Michael S. Branicky, Nov 14 2021

Crossrefs

Cf. A025060 (without repetitions), A093669.

Sequence in context: A239935 A219179 A221281 * A025060 A093669 A084805

Adjacent sequences: A025055 A025056 A025057 * A025059 A025060 A025061

Keyword

nonn

Author

Clark Kimberling

Status

approved