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 A175983 Squares n^2 that become prime after omitting all ones in their decimal expansion. 0
 121, 1089, 11449, 21609, 31329, 56169, 117649, 127449, 131769, 139129, 142129, 154449, 178929, 199809, 431649, 471969, 751689, 1014049, 1159929, 1172889, 1194649, 1530169, 1841449, 2211169, 2411809, 2518569, 2634129, 3108169, 3143529 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Corresponding values of n are 11, 33, 107, 147, 177, 237, 343, 357, 363, 373, 377, 393, 423, 447, 657, 687, 867, 1007, 1077, 1083, .... The resulting primes are 2, 89, 449, 2609, 3329, 5669, 7649, 27449, 3769, 3929, 4229, 54449, 78929, 99809, 43649, 47969, 75689, .... LINKS Table of n, a(n) for n=1..29. MATHEMATICA Reap[Do[If[PrimeQ[FromDigits[DeleteCases[IntegerDigits[n^2], 1]]], Sow[n^2]], {n, 5000}]][[2, 1]] PROG (Magma) remove1:=func< n | [ d: d in n | d ne 1 ] >; [ s: n in [1..3400] | IsPrime(Seqint(remove1(Intseq(s)))) where s is n^2 ]; CROSSREFS Sequence in context: A243810 A302561 A120353 * A307858 A329100 A208261 Adjacent sequences: A175980 A175981 A175982 * A175984 A175985 A175986 KEYWORD nonn,base AUTHOR Zak Seidov, Dec 08 2010 STATUS approved

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Last modified May 19 11:18 EDT 2024. Contains 372683 sequences. (Running on oeis4.)