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A124979 Numbers in A118882 for which 5 is not a divisor. 2
169, 221, 289, 338, 377, 442, 481, 493, 533, 578, 629, 676, 689, 697, 754, 793, 841, 884, 901, 949, 962, 986, 1037, 1066, 1073, 1156, 1157, 1189, 1241, 1258, 1261, 1313, 1352, 1369, 1378, 1394, 1417, 1469, 1508, 1513, 1517 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
PROG
(Python)
from itertools import count, islice
from math import prod
from sympy import factorint
def A124979_gen(startvalue=1): # generator of terms >= startvalue
for n in count(max(startvalue, 1)):
f = factorint(n)
if n%5 and 1<int(not any(e&1 for e in f.values())) + (((m:=prod(1 if p==2 else (e+1 if p&3==1 else (e+1)&1) for p, e in f.items()))+((((~n & n-1).bit_length()&1)<<1)-1 if m&1 else 0))>>1):
yield n
A124979_list = list(islice(A124979_gen(), 30)) # Chai Wah Wu, Sep 09 2022
CROSSREFS
Cf. A118882.
Sequence in context: A038512 A350705 A141075 * A292559 A322568 A350381
KEYWORD
nonn
AUTHOR
Artur Jasinski, Nov 15 2006
EXTENSIONS
Corrected and extended by M. F. Hasler, Feb 08 2009
Further corrections following an observation by P. McNab, by M. F. Hasler, Jul 08 2015
STATUS
approved

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Last modified March 29 08:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)