A276756 Squarefree terms of A276655.

1, 21, 30, 979, 1411, 1463, 1547, 1742, 1947, 2059, 2090, 2210, 2318, 2405, 2419, 2491, 2703, 2886, 2945, 3182, 3243, 3534, 3567, 16102, 17654, 20559, 21243, 25543, 25705, 27145, 27307, 27805, 28045, 29323, 29370, 29631, 30485, 30846, 32574, 33366, 33465, 33654

Offset

1,2

Comments

Except for the first term, products of distinct primes p_i such that Sum_{p_i} 0.p_i is an integer.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Formula

A005117 INTERSECT A276655.

Prog

(Python)
from fractions import Fraction
from sympy import factorint, primefactors
A276756_list = [1] + [n for n in range(2, 10**6) if max(factorint(n).values()) <= 1 and sum(Fraction(p, 10**len(str(p))) for p in primefactors(n)).denominator == 1]

Crossrefs

Cf. A005117, A276655.

Sequence in context: A187965 A318349 A228142 * A115433 A116096 A116116

Adjacent sequences: A276753 A276754 A276755 * A276757 A276758 A276759

Keyword

nonn

Author

Chai Wah Wu, Sep 17 2016

Status

approved