20485

Appears in sequences

• Denominators of continued fraction convergents to sqrt(41).at n=8A041069
• Denominators of continued fraction convergents to sqrt(164).at n=8A041303
• Denominators of continued fraction convergents to sqrt(369).at n=8A041699
• Denominators of continued fraction convergents to sqrt(656).at n=14A042261
• Base-8 palindromes that start with 5.at n=18A043025
• Numbers whose base-4 representation contains exactly four 0's and four 1's.at n=20A045037
• Family 1 "Rule 90 x Rule 150 Array" read by antidiagonals.at n=32A048710
• a(n) is the smallest index m such that Sum_{k=2..m} 1/PrimePi(k) >= n, where PrimePi()=A000720().at n=43A074633
• a(n) = (n-2) * 2^(n-1) + 5.at n=12A098821
• Expansion of (1+t^2+4*t^3+2*t^4+t^5+3*t^6)/((1-t)^2*(1-t^2)*(1-t^3)^2).at n=28A100779
• A106486-encodings of combinatorial games with value 2.at n=25A125995
• Ulam's spiral (ESE spoke).at n=36A143855
• Numbers k such that 2^(2k-1) == 2 (mod 2k) and such that 2^(k-1) != 1 (mod k).at n=35A176033
• Subgroups of nimber addition interpreted as binary numbers.at n=45A190939
• Hypotenuses of primitive Pythagorean triples in A195565 and A195566.at n=6A195567
• Hypotenuses of primitive Pythagorean triples in A195580 and A195611.at n=3A195612
• Numbers n palindromic in exactly three bases b, 2 <= b <= 10.at n=43A214425
• Numbers n such that 3^6*2^n - 1 is prime.at n=20A230527
• a(n) = 5*2^n + 5.at n=12A231643
• Palindromic numbers in bases 2 and 8 written in base 10.at n=41A259380