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A340570 Averages k of twin prime pairs such that A075255(k) is also the average of a twin prime pair. 1
42, 72, 348, 1998, 4722, 9282, 28182, 34128, 34962, 46818, 46830, 57348, 59442, 71328, 79398, 81552, 97860, 113160, 115602, 117618, 138798, 151008, 157218, 158748, 179898, 183510, 184902, 185070, 234810, 244158, 245418, 284130, 316698, 328062, 335382, 337872, 343830, 351258, 357780, 425442 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Terms k of A075255 such that A014574(k) is in A075255.
LINKS
EXAMPLE
a(3) = 348 is a term because A014574(348) = 348-(2+2+3+29) = 312 and 348-1 = 347, 348+1 = 349, 312-1 = 311, and 312+1 = 313 are prime.
MAPLE
filter:= proc(n) local s, t;
if not isprime(n-1) or not isprime(n+1) then return false fi;
s:= add(t[1]*t[2], t= ifactors(n)[2]);
isprime(n-s-1) and isprime(n-s+1)
end proc:
select(filter, [seq(i, i=6..10^6, 2)]);
CROSSREFS
Sequence in context: A340384 A330893 A305153 * A261621 A043689 A043573
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jan 11 2021
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)