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A172245 a(n) = Number of partitions n on sum a + b such that a<=b and gcd(a,b,n)=1 and having different values of function N(a,b,n) defined as product different prime divisors of a*b*n. 3
1, 1, 1, 2, 1, 2, 2, 3, 2, 4, 2, 5, 3, 3, 4, 7, 3, 7, 4, 5, 5, 8, 4, 8, 6, 9, 6, 13, 4, 12, 8, 10, 8, 10, 6, 16, 9, 11, 7, 18, 6, 19, 10, 12, 11, 19, 8, 18, 10, 16, 12, 23, 9, 17, 12, 17, 13, 27, 8, 26, 15, 17, 16, 21, 10, 30, 16, 22, 12, 29, 12, 30, 18, 20, 18, 26, 12, 34, 16, 27, 20, 38 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,4

COMMENTS

Number of partitions n on sum a + b such that a<=b gcd(a,b,n)=1 see: A023022

Number of partitions having that same value of function N(a,b,n) see: A172246

Numbers n for which existed cases with that same value of function N(a,b,n) see: A172247

Numbers n for which all partitions have different value of function N(a,b,n) see: A172248.

LINKS

Table of n, a(n) for n=2..83.

EXAMPLE

a(5)=2 because we have two partitions 5=1+4 and 5=2+3 with different values of N(a,b,n) respectively 1*2*5=10 and 2*3*5=30.

CROSSREFS

A023022, A172246, A172247, A172248.

Sequence in context: A060426 A260412 A283451 * A238781 A319439 A051275

Adjacent sequences:  A172242 A172243 A172244 * A172246 A172247 A172248

KEYWORD

nonn

AUTHOR

Artur Jasinski, Jan 29 2010

STATUS

approved

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Last modified May 31 07:22 EDT 2020. Contains 334747 sequences. (Running on oeis4.)