OFFSET
1,1
COMMENTS
Also numbers n such that the sum of prime indices of n minus the greater of the number of prime factors of n counted with multiplicity and the largest prime index of n is 1. A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798, and their sum is A056239.
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
EXAMPLE
The sequence of terms together with their prime indices begins:
6: {1,2}
10: {1,3}
12: {1,1,2}
14: {1,4}
22: {1,5}
24: {1,1,1,2}
26: {1,6}
34: {1,7}
38: {1,8}
46: {1,9}
48: {1,1,1,1,2}
58: {1,10}
62: {1,11}
74: {1,12}
82: {1,13}
86: {1,14}
94: {1,15}
96: {1,1,1,1,1,2}
106: {1,16}
118: {1,17}
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Select[Range[100], Total[primeMS[#]]-Max[Length[primeMS[#]], Max[primeMS[#]]]==1&]
PROG
(Python)
from sympy import isprime
A325231_list = [n for n in range(6, 10**6) if ((not n % 2) and isprime(n//2)) or (bin(n)[2:4] == '11' and bin(n).count('1') == 2)] # Chai Wah Wu, Apr 16 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 13 2019
STATUS
approved