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# User:José de Jesús Camacho Medina

### From OeisWiki

I was born in Fresnillo Zacatecas Mexico, early I became interested in the Prime Numbers; those mathematical entities that have derided the order and the brightest minds of all times.I studied Engineering subsequently a Masters in Mathematics, to my 29 years I'm dedicated to teaching and investigation.In this site you can find part of my research: http://matematicofresnillense.blogspot.mx/

I love the patterns and the sequences.

Some of my contributions in OEIS.org and other:

**RECURRENCE FORMULA TO TEST IF A NUMBER IS HAPPY.**

b_{1}the number to test. Ifb_{f}= 1 , after some iterations is then consideredb_{1}is a happy number.

- .

You can check: [**A007770**]

**SEQUENCE FRESNILLENSES NUMBERS (NÚMEROS FRESNILLENSES) .**

Numbers that are equal to the sum of their digits raised to each power from 1 to the number of digits. 1, 2, 3, 4, 5, 6, 7, 8, 9, 90, 336, 4538775, 183670618662, 429548754570, 3508325641459, 3632460407839, 9964270889420, 10256010588126...

For example:

9 = 9^{1}

90 = (9^{1} + 0^{1}) + (9^{2} + 0^{2})

336 = (3^{1} + 3^{1} + 6^{1}) + (3^{2} + 3^{2} + 6^{2}) + (3^{3} + 3^{3} + 6^{3})

You can check: [**A240511**]

**FORMULA FOR SEQUENCE : NUMBERS THAT CONTAIN ONLY ONE NONZERO DIGIT. **

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000...

You can check: [**A037124**]

**FORMULA FOR THE SEQUENCE CONCATENATE OF NATURALS N TIMES (SMARANDACHE SEQUENCE).**

1, 22, 333, 4444, 55555, 666666, 7777777, 88888888, 999999999, 10101010101010101010...

You can check: [**A000461**]

**FORMULA FOR THE DIGITAL SUM OF A NUMBER**

You can check: [**A007953**]

**FORMULA FOR THE PRODUCT OF DECIMAL DIGITS OF n.**

You can check: [**A007954**]

**FORMULA FOR THE SEQUENCE REPDIGIT NUMBERS .**

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 111, 222, 333, 444, 555, 666, 777, 888, 999, 1111, 2222, 3333...

You can check: [**A010785**]

**FORMULA FOR THE SEQUENCE NUMBERS n SUCH THAT n EQUALS THE SUM OF ITS DIGITS RAISED TO THE CONSECUTIVE POWERS(1,2,3,...).**

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 89, 135, 175, 518, 598, 1306, 1676...

For example:

`2427 = 2`^{1} + 4^{2} + 2^{3} + 7^{4}.

**Let**

**If a(n)=0, then 'n' is a number of this sequence**

You can check: [**A032799**]

**FORMULA FOR THE SEQUENCE OF NARCISSISTIC NUMBERS**

1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208...

For example:

`153 = 1`^{3} + 5^{3} + 3^{3}

**Let**

**If a(x)=0, then 'x' is a Narcissistic number**

You can check: [**A005188**]

**FORMULA FOR THE SEQUENCE OF NUMBERS WRITTEN IN BASE 2.**

0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010, 1011, 1100, 1101, 1110, 1111..

You can check: [**A007088**]

**FORMULA FOR THE SEQUENCE READ n BACKWARDS**

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 2, 12...

You can check: [**A004086**]

**FORMULA DIGITAL ROOT OF n**

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2...

You can check: [**A010888**]

**FORMULA OF CONGRUENT TO 0 OR 1 MOD 5.**

0, 1, 5, 6, 10, 11, 15, 16, 20, 21, 25, 26, 30, 31, 35, 36, 40, 41, 45, 46, 50, 51, 55...

You can check: [**A008851**]

**SEQUENCE WITH MANY PRIME NUMBERS AND ZEROS**

1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 0, 0, 29, 0, 31, 0, 0, 0, 0, 0, 0, 0, 0, 0, 41...

You can check: [**A245515**]

**FORMULA SIEVE OF ERATOSTHENES WITH FUNCTIONS MOD AND GCD (PRIME NUMBERS)**

The Formula Produces Prime Numbers and Zeros , check this article:[1]

**SEQUENCE OF SUM OF THE FIRST 10^n PRIMES.**

**For i>=0.**

You can check: [**A099824**]

**FORMULA FOR CALCULATING PI APPROXIMATED WITH SIX DIGITS OF PRECISION INCLUDED GOLDEN RATIO AND EULER NUMBER**

**MAGIC TRIANGLES WITH PRIMES NUMBER**

You can check: [2]

**SEQUENCE a(n) IS THE CONCATENATION OF FIRST n TERMS **

1, 12, 123, 1234, 12345, 123456, 1234567, 12345678, 123456789, 1234567891, 12345678910, 123456789101, 1234567891011,...

You can check: [**A252043**]