Numbers whose binary and ternary digit sums are prime
Numbers whose binary and ternary digit sums are prime is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
- Task
- Show numbers which binary and ternary digit sum are prime, where n < 200
Ring
<lang ring> load "stdlib.ring"
see "working..." + nl
decList = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15] baseList = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"]
limit = 200
for n = 1 to limit
strBin = decimaltobase(n,2) strTer = decimaltobase(n,3) sumBin = 0 for m = 1 to len(strBin) sumBin = sumBin + number(strBin[m]) next sumTer = 0 for m = 1 to len(strTer) sumTer = sumTer + number(strTer[m]) next if isprime(sumBin) and isprime(sumTer) see "{" + n + "," + strBin + ":" + sumBin + "," + strTer + ":" + sumTer + "}" + nl ok
next
see "done..." + nl
func decimaltobase(nr,base)
binList = [] binary = 0 remainder = 1 while(nr != 0) remainder = nr % base ind = find(decList,remainder) rem = baseList[ind] add(binList,rem) nr = floor(nr/base) end binlist = reverse(binList) binList = list2str(binList) binList = substr(binList,nl,"") return binList
</lang>
- Output:
working... {5,101:2,12:3} {6,110:2,20:2} {7,111:3,21:3} {10,1010:2,101:2} {11,1011:3,102:3} {12,1100:2,110:2} {13,1101:3,111:3} {17,10001:2,122:5} {18,10010:2,200:2} {19,10011:3,201:3} {21,10101:3,210:3} {25,11001:3,221:5} {28,11100:3,1001:2} {31,11111:5,1011:3} {33,100001:2,1020:3} {35,100011:3,1022:5} {36,100100:2,1100:2} {37,100101:3,1101:3} {41,101001:3,1112:5} {47,101111:5,1202:5} {49,110001:3,1211:5} {55,110111:5,2001:3} {59,111011:5,2012:5} {61,111101:5,2021:5} {65,1000001:2,2102:5} {67,1000011:3,2111:5} {69,1000101:3,2120:5} {73,1001001:3,2201:5} {79,1001111:5,2221:7} {82,1010010:3,10001:2} {84,1010100:3,10010:2} {87,1010111:5,10020:3} {91,1011011:5,10101:3} {93,1011101:5,10110:3} {97,1100001:3,10121:5} {103,1100111:5,10211:5} {107,1101011:5,10222:7} {109,1101101:5,11001:3} {115,1110011:5,11021:5} {117,1110101:5,11100:3} {121,1111001:5,11111:5} {127,1111111:7,11201:5} {129,10000001:2,11210:5} {131,10000011:3,11212:7} {133,10000101:3,11221:7} {137,10001001:3,12002:5} {143,10001111:5,12022:7} {145,10010001:3,12101:5} {151,10010111:5,12121:7} {155,10011011:5,12202:7} {157,10011101:5,12211:7} {162,10100010:3,20000:2} {167,10100111:5,20012:5} {171,10101011:5,20100:3} {173,10101101:5,20102:5} {179,10110011:5,20122:7} {181,10110101:5,20201:5} {185,10111001:5,20212:7} {191,10111111:7,21002:5} {193,11000001:3,21011:5} {199,11000111:5,21101:5} done...