A236515 Colexicographic index of prime signature of n.

1, 2, 2, 3, 2, 4, 2, 5, 3, 4, 2, 6, 2, 4, 4, 8, 2, 5, 2, 6, 4, 4, 2, 9, 3, 4, 5, 6, 2, 7, 2, 13, 4, 4, 4, 10, 2, 4, 4, 9, 2, 7, 2, 6, 6, 4, 2, 14, 3, 5, 4, 6, 2, 8, 4, 9, 4, 4, 2, 11, 2, 4, 6, 20, 4, 7, 2, 6, 4, 7, 2, 15, 2, 4, 5, 6, 4, 7, 2, 14, 8, 4, 2, 11, 4, 4, 4, 9, 2, 10, 4, 6, 4, 4, 4, 21, 2, 5, 6, 10

Offset

1,2

Comments

Index of prime signature of n when prime signatures are listed in colexicographic order (see A036037).

Links

Table of n, a(n) for n=1..100.

OEIS Wiki, Orderings of prime signature

Example

a(7) = a({1}) = 2, a(180) = a({2,2,1}) = 17, a(216) = a({3,3}) = 23
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a(1) = 1,
For all n in A000040, prime_signature(n) = {1}, a(n) = 2,
For all n in A001248, prime_signature(n) = {2}, a(n) = 3,
For all n in A006881, prime_signature(n) = {1,1}, a(n) = 4,
For all n in A030078, prime_signature(n) = {3}, a(n) = 5,
For all n in A054753, prime_signature(n) = {2,1}, a(n) = 6,
For all n in A007304, prime_signature(n) = {1,1,1}, a(n) = 7, etc.

Crossrefs

Cf. A036037, A124010, A237433.

Sequence in context: A300250 A319357 A237433 * A318469 A300224 A304103

Adjacent sequences: A236512 A236513 A236514 * A236516 A236517 A236518

Keyword

nonn

Author

Sung-Hyuk Cha, Jan 27 2014

Status

approved