23331

Appears in sequences

• Number of positive integers <= 2^n of form x^2 + 4 y^2.at n=17A000072
• Related to Gilbreath conjecture.at n=29A001549
• Denominators of continued fraction convergents to sqrt(459).at n=9A041875
• Odd numbers with exactly 4 distinct palindromic prime factors.at n=8A046406
• List of molecules in Hintze-Adami artificial chemistry (see comments for definition).at n=18A101145
• Triangle read by rows: T(n,k) = n*(1+n^k)/2, 0<=k<=n.at n=26A108396
• a(n) = (n^n + n)/2.at n=5A117694
• a(n) = n*(n^5 + 1)/2.at n=6A167963
• Terms in A177950 that are not in A002778.at n=43A175440
• Numbers k whose sum of digits equals the period of 1/k.at n=38A178495
• Smallest multiple of n whose factorial digit sum equals n.at n=20A191895
• Divisors of the repunit 111111111111 = A002275(12).at n=44A197318
• a(n) = n*(n + 1)*(5*n - 4)/2.at n=21A237616
• Numbers n such that n^10+10 is prime.at n=37A239347
• Numbers n whose sum of anti-divisors is a permutation of their digits.at n=35A258786
• a(n) = (Product_{i=0..4}(i*n+2) - Product_{i=0..4}(-i*n-1))/(4*n+3).at n=10A274119
• Positions of 3's in A264977; positions of 6's in A277330.at n=42A277713
• Numbers of the form k*(k^5 +- 1)/2.at n=11A361263
• Expansion of 1/(1 - x*(1 + x)^3)^3.at n=8A382614
• Left-truncatable happy numbers: every suffix is a happy number and no digits are zero.at n=20A383639