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 A276567 Odd squares not of the form p + 2^k with p prime. 1
 1, 40401, 62001, 96721, 121801, 192721, 326041, 410881, 555025, 660969, 683929, 772641, 786769, 822649, 1343281, 1390041, 1530169, 1739761, 1885129, 1923769, 1962801, 2283121, 2544025, 2913849, 3207681, 3214849, 3352561, 3396649, 3613801, 3775249, 3853369, 4060225 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The sequence contains also Sierpiński numbers (i.e., 4521731193704761, 60428287050225649). LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA A006285 INTERSECT A016754. MAPLE filter:= proc(n) local k; for k from 0 to ilog2(n) do if isprime(n - 2^k) then return false fi od: true end proc: select(filter, [seq((2*i+1)^2, i=0..10^4)]); # Robert Israel, Sep 07 2016 MATHEMATICA filterQ[n_] := Module[{k}, For[k = 0, k <= Log[2, n], k++, If[PrimeQ[n - 2^k], Return[False]]]; True]; Select[Table[(2i+1)^2, {i, 0, 10^4}], filterQ] (* Jean-François Alcover, Oct 06 2020, after Maple *) PROG (Magma) lst:=[]; for s in [1..2015 by 2] do n:=s^2; x:=0; repeat x+:=1; a:=n-2^x; until a lt 1 or IsPrime(a); if a lt 1 then Append(~lst, n); end if; end for; lst; CROSSREFS Cf. A006285, A016754. Sequence in context: A229675 A250905 A250949 * A216291 A216290 A237970 Adjacent sequences: A276564 A276565 A276566 * A276568 A276569 A276570 KEYWORD nonn AUTHOR Arkadiusz Wesolowski, Sep 06 2016 STATUS approved

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Last modified June 4 23:50 EDT 2023. Contains 363130 sequences. (Running on oeis4.)