

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
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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



KEYWORD

nonn,base


AUTHOR



STATUS

approved



