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A138026 Where A121561(n) = 3. 3
122, 123, 148, 190, 208, 209, 220, 221, 250, 292, 302, 303, 326, 327, 346, 418, 430, 476, 477, 518, 519, 532, 533, 538, 539, 556, 586, 628, 629, 640, 670, 671, 700, 718, 782, 783, 796, 806, 807, 820, 838, 848, 849, 872, 873, 896, 897, 902, 903, 928, 962 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MAPLE
filter:= proc(n)
local t;
t:= n-prevprime(n+1);
if t <= 1 then return false fi;
t:= t-prevprime(t+1);
if t <= 1 then return false fi;
isprime(t) or isprime(t-1)
end proc:
select(filter, [$2..1000]); # Robert Israel, Jan 15 2019
MATHEMATICA
LrgstPrm[n_] := Block[{k = n}, While[ !PrimeQ@k, k-- ]; k]; f[n_] := Block[{c = 0, d = n}, While[d > 1, d = d - LrgstPrm@ d; c++ ]; c]; lst = {} Do[ If[f@n == 3, AppendTo[lst, n], {n, 10^4}]; lst
CROSSREFS
Sequence in context: A296886 A077376 A194565 * A077030 A280733 A309760
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Feb 27 2008
STATUS
approved

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Last modified April 13 12:46 EDT 2024. Contains 371641 sequences. (Running on oeis4.)