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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
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
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.)