Self Number
Lambert M. Surhone, Miriam T. Timpledon, Susan F. Marseken
High Quality Content by WIKIPEDIA articles! .A self number, Colombian number or Devlali number is an integer which, in a given base, cannot be generated by any other integer added to the sum of that other integer's digits. For example, 21 is not a self number, since it can be generated by the sum of 15 and the digits comprising 15, that is, 21 = 15 + 1 + 5. No such sum will generate the integer 20, hence it is a self number. These numbers were first described in 1949 by the Indian mathematician D. R. Kaprekar.In general, for even bases, all odd numbers below the base number are self numbers, since any number below such an odd number would have to also be a 1-digit number which when added to its digit would result in an even number. For...
ISBN: 978-6-1311-7265-6
Издательство:
Книга по требованию
Дата выхода: июль 2011