The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A361215 Intersection of A361073 and 2 * A361611. 2
8, 20, 50, 1406, 1516, 1558, 1868, 1898, 1948, 1978, 1986, 5862, 5972, 6014, 7122, 7966, 7996, 8270, 8348, 8366, 8548, 8618, 21092, 31804, 31822, 32158, 33092, 33162, 33316, 33414, 37124, 37190, 37292, 37394, 39164, 39214, 39316, 39346, 39484, 39562, 39604, 39622, 39692, 39794, 45044, 45244 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If A361073(j) = 2*A361611(k) then x = 2*A361611(k+1) has the property that x, x - A361073(j) and x + A361073(j) are triprimes, so x >= A361073(j+1), with equality if and only if A361073(j+1) is even.
LINKS
EXAMPLE
a(4) = 1406 is a term because 1406 = A361073(20) = 2*A361611(17).
MAPLE
A:= {8}: lasta:= 8:
for i from 2 to 1000 do
for x from lasta+8 do
if numtheory:-bigomega(x) = 3 and numtheory:-bigomega(x-lasta) = 3 and numtheory:-bigomega(x+lasta) = 3 then
A:= A union {x}; lasta:= x; break
fi
od od:
R:= {8}: lastb:= 4:
while 2*lastb < lasta do
for x from lastb+4 do
if numtheory:-bigomega(x) = 2 and numtheory:-bigomega(x-lastb) = 2 and numtheory:-bigomega(x+lastb) = 2 then
if member(2*x, A) then R:= R union {2*x} fi;
lastb:= x; break
fi
od od:
sort(convert(R, list));
CROSSREFS
Sequence in context: A169878 A107816 A361073 * A205219 A232401 A036835
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Apr 09 2023
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 21 05:34 EDT 2024. Contains 372728 sequences. (Running on oeis4.)