A343735 Odd palindromes having more divisors than all smaller odd palindromes.
1, 3, 9, 33, 99, 525, 3003, 5445, 5775, 50505, 53235, 171171, 525525, 5073705, 18999981, 50555505, 51666615, 512272215, 513828315, 5026226205, 5053553505, 5184994815, 5708778075, 52252425225, 502299992205, 502875578205, 524241142425, 579024420975
Offset: 1
Examples
no. of n a(n) prime factorization divisors -- ---------- --------------------------------- -------- 1 1 - 1 2 3 3 2 3 9 3^2 3 4 33 3 * 11 4 5 99 3^2 * 11 6 6 525 3 * 5^2 * 7 12 7 3003 3 * 7 * 11 * 13 16 8 5445 3^2 * 5 * 11^2 18 9 5775 3 * 5^2 * 7 * 11 24 10 50505 3 * 5 * 7 * 13 * 37 32 11 53235 3^2 * 5 * 7 * 13^2 36 12 171171 3^2 * 7 * 11 * 13 * 19 48 13 525525 3 * 5^2 * 7^2 * 11 * 13 72 14 5073705 3^3 * 5 * 7^2 * 13 * 59 96 15 18999981 3^3 * 7 * 11 * 13 * 19 * 37 128 16 50555505 3 * 5 * 7^2 * 11 * 13^2 * 37 144 17 51666615 3^2 * 5 * 7 * 11 * 13 * 31 * 37 192 18 512272215 3^3 * 5 * 7^3 * 13 * 23 * 37 256 19 513828315 3^2 * 5 * 7 * 11^2 * 13 * 17 * 61 288 20 5026226205 3 * 5 * 7^2 * 11 * 13 * 17 * 29 * 97 384
Links
- Jon E. Schoenfield, Table of n, a(n) for n = 1..49
Comments