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A104230 Minimal number of primes needed to sum to n^2. 0
2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
COMMENTS
For the Goldbach conjecture every even number that is greater than 2 is the sum of three primes and odd number is the sum of three primes, no term is greater 3.
LINKS
Eric Weisstein's World of Mathematics, Goldbach Conjecture .
FORMULA
a(n) = A051034(A000290(n)). - Michel Marcus, Jun 04 2013
EXAMPLE
a(2)=2 because 2^2=2+2;
a(3)=2 because 3^2=2+7.
CROSSREFS
Sequence in context: A349925 A339171 A083311 * A226774 A037968 A303378
KEYWORD
easy,nonn
AUTHOR
Giovanni Teofilatto, Apr 02 2005
EXTENSIONS
Corrected and extended by Michel Marcus, Jun 04 2013
STATUS
approved

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Last modified March 28 12:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)