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 A225151 Squares which are a decimal concatenation of triprimes. 1
 12544, 15376, 19044, 20164, 27556, 28561, 42436, 45369, 45796, 75076, 81796, 86436, 87025, 89401, 98596, 114244, 116964, 123201, 124609, 125316, 126025, 127449, 128164, 131044, 139876, 141376, 150544, 174724, 175561, 184041, 188356, 190969, 191844, 207025 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Christian N. K. Anderson, Table of n, a(n) for n = 1..10000 Christian N. K. Anderson, Table of n, a(n), sqrt(a(n)), all possible separations of a(n) into triprimes EXAMPLE a(10) is 75076, which splits into 75|076. 75 = 3*5*5; 76 = 2*2*19. PROG (R) library(gmp); istriprime=function(x) ifelse(x<8, F, length(factorize(x))==3) splithasproperty<-function(n, FUN, curdig=1, res=list(), curspl=c()) { no0<-function(s){ while(substr(s, 1, 1)=="0" & nchar(s)>1) s=substr(s, 2, nchar(s)); s} s=as.character(n) if(curdig>nchar(s)) return(res) if(length(curspl)>0) if(FUN(as.bigz(no0(substr(s, curdig, nchar(s)))))) res[[length(res)+1]]=curspl for(i in curdig:nchar(s)) if(FUN(as.bigz(no0(substr(s, curdig, i))))) res=splithasproperty(n, FUN, i+1, res, c(curspl, i)) res } which(sapply(1:500, function(x) length(splithasproperty(x^2, istriprime)))>0)^2 CROSSREFS Cf. A014612, A030459, A030461, A000290, A019547. Sequence in context: A252164 A045217 A298313 * A237907 A251296 A205757 Adjacent sequences: A225148 A225149 A225150 * A225152 A225153 A225154 KEYWORD nonn,base AUTHOR Kevin L. Schwartz and Christian N. K. Anderson, Apr 30 2013 STATUS approved

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Last modified September 27 02:54 EDT 2023. Contains 365669 sequences. (Running on oeis4.)