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A367084
Indices k such that A367083(k) and A367083(k+1) are both odd.
3
0, 7, 16, 25, 34, 43, 50, 59, 68, 77, 86, 95, 102, 111, 120, 129, 138, 145, 154, 163, 172, 181, 190, 197, 206, 215, 224, 233, 240, 249, 258, 267, 276, 285, 292, 301, 310, 319, 328, 335, 344, 353, 362, 371, 380, 387, 396, 405, 414, 423, 430, 439, 448, 457, 466, 475, 482, 491, 500
OFFSET
0,2
COMMENTS
First differences are either 7 (in isolated positions) or 9 (always 4 or 5 times consecutively in a row). It is interesting to study these run lengths, see A367083 for further information.
PROG
(PARI) A367084_upto(N) = [n|n<-A=A367083_upto(N), A[n+1]==Mod(A[n], 2)]
(Python)
from itertools import islice
def A367084_gen(): # generator of terms
a, b, c = 1, 4, -1
while True:
while (a:=a*3)<b:
yield (c:=c+1)
b <<= 2
c += 2
A367084_list = list(islice(A367084_gen(), 30)) # Chai Wah Wu, Nov 08 2023
CROSSREFS
Sequence in context: A114556 A136772 A190371 * A273159 A043481 A217009
KEYWORD
nonn
AUTHOR
M. F. Hasler, Nov 03 2023
STATUS
approved