22001

Appears in sequences

• Number of partitions of n that do not contain 2 as a part.at n=44A027336
• A064637 converted to factorial base.at n=17A064477
• Smallest multiple of n with digit sum = 5, or 0 if no such number exists, e.g. a(3k) = a(11k) = 0.at n=48A069524
• Number of partitions of n-th composite number not containing the smallest prime factor.at n=28A091094
• Greater of number pair whose squares are reversals of each other, with no leading zeros allowed.at n=33A106324
• Number of permutations P of 1..n such that in P and in the inverse of P, every pair of adjacent numbers are relatively prime.at n=11A117541
• Increasing gaps in the even sieve (A056533) by lower term.at n=20A119503
• Sum of all repeated parts of all partitions of n.at n=22A163986
• a(n) = A002865(2*n-1)+A002865(2*n).at n=21A182845
• Sums of antidiagonals of A223968.at n=15A223940
• Number of (n+2)X4 0..2 matrices with each 3X3 subblock idempotent.at n=14A224600
• A239461(n) / n^2.at n=21A239464
• Sequence A261220 shown in factorial base: a(n) = A007623(A261220(n)).at n=41A260743
• E.g.f. S(x) satisfies: C(x)^2 - S(x)^2 = 1 and D(x)^3 - S(x)^3 = 1, where functions C(x) and D(x) are described by A280621 and A280622, respectively.at n=8A280620
• Expansion of Sum_{i>=1} mu(i)^2*i*x^i/(1 - x^i) / Product_{j>=1} (1 - x^j), where mu() is the Moebius function (A008683).at n=22A281904
• Length of n-th iterate of the mapping 00->0010, 01->100, 10->000 in A289235.at n=16A289153
• Numbers m such that d(1)^1 + d(2)^2 + ... + d(p)^k = d(1)! + d(2)! + ... + d(k)!, where d(i), i=1..k, are the digits of m.at n=34A342945
• Ternary numbers consisting of a run of 2's, then a run of 0's, then a run of 1's.at n=7A371057
• Ternary numbers that are concatenated runs C(1)B(1)A(1)C(2)B(2)A(2)...C(k)B(k)A(k), where A(i) is a run of 1's, B(i) a run of 0's, and C(i) a run of 2's, for i = 1..k.at n=7A371109
• Coefficient of x^n in the expansion of ( (1+x+x^3)^2 / (1+x) )^n.at n=10A372371