What is Disarium number?
A number is called Disarium if sum of its digits powered with their respective positions is equal to the number itself.
How do you get a happy number in C++?
In the above program to check happy numbers in c++ or not using function: A number is said to be Happy if and only if the sum of the square of its digits is equal to one. For example: 10 is a happy number. Because when the square of its digits are added, 12+02=1, we get 1.
Why is the number 7 so happy?
Iterating this sum-of-squared-digits map always eventually reaches one of the 10 numbers 0, 1, 4, 16, 20, 37, 42, 58, 89, or 145 (OEIS A039943; Porges 1945). is said to be happy. For example, starting with 7 gives the sequence 7, 49, 97, 130, 10, 1, so 7 is a happy number.
Is 42 a harshad number?
Harshad numbers in base 10 form the sequence: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20, 21, 24, 27, 30, 36, 40, 42, 45, 48, 50, 54, 60, 63, 70, 72, 80, 81, 84, 90, 100, 102, 108, 110, 111, 112, 114, 117, 120, 126, 132, 133, 135, 140, 144, 150, 152, 153, 156, 162, 171, 180, 190, 192, 195, 198, 200.
What is happy number example?
For example, starting with 7 gives the sequence 7, 49, 97, 130, 10, 1, so 7 is a happy number. The first few happy numbers are 1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49, 68, 70, 79, 82, 86, 91, 94, 97, 100, (OEIS A007770). These are also the numbers whose 2-recurring digital invariant sequences have period 1.
How is 7 a happy number?
Is 666 a Smith number?
The first few Smith numbers in base 10 are: 4, 22, 27, 58, 85, 94, 121, 166, 202, 265, 274, 319, 346, 355, 378, 382, 391, 438, 454, 483, 517, 526, 535, 562, 576, 588, 627, 634, 636, 645, 648, 654, 663, 666, 690, 706, 728, 729, 762, 778, 825, 852, 861, 895, 913, 915, 922, 958, 985, 1086 … (sequence A006753 in the OEIS)
Why is 7 a happy number?
Why is 6 a perfect number?
In number theory, a perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. For instance, 6 has divisors 1, 2 and 3 (excluding itself), and 1 + 2 + 3 = 6, so 6 is a perfect number.
Is 6 an amicable number?
Fermat and Descartes also rediscovered pairs of amicable numbers known to Arab mathematicians. Euler also discovered dozens of new pairs. The second smallest pair, (1184, 1210), was discovered in 1867 by 16-year-old B….History.
# | m | n |
---|---|---|
6 | 10,744 | 10,856 |
7 | 12,285 | 14,595 |
8 | 17,296 | 18,416 |
9 | 63,020 | 76,084 |