27521
domain: N
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 13.at n=23A031601
- a(n) = the number of occurrences of 1 in all compositions of n without 2's = # of occurrences of the integer k in compositions of n+k-1 without 2's (k > 2).at n=16A079662
- Composite squarefree numbers n such that p(i)-10 divides n+10, where p(i) are the prime factors of n.at n=27A225710
- Number of 2 X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.at n=9A268887
- Number of nX2 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.at n=4A278628
- Number of nX5 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.at n=1A278631
- T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.at n=16A278634
- T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.at n=19A278634
- MM-numbers of labeled simple graphs spanning an initial interval of positive integers.at n=11A320458
- MM-numbers of labeled multigraphs spanning an initial interval of positive integers.at n=17A320459
- MM-numbers of labeled graphs with loops spanning an initial interval of positive integers.at n=33A320461
- MM-numbers of labeled simple hypergraphs with no singletons spanning an initial interval of positive integers.at n=31A320463
- MM-numbers of labeled multi-hypergraphs with no singletons spanning an initial interval of positive integers.at n=39A320464
- MM-numbers of simple labeled connected graphs spanning an initial interval of positive integers.at n=7A320635
- Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.at n=26A334557