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A283248 Numbers that cannot be represented as a sum of one prime and two primes squared. 1
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 17, 22, 28, 33, 38, 43, 62, 68, 78, 83, 98, 104, 134, 146, 158, 174, 179, 182, 188, 200, 218, 230, 248, 260, 266, 272, 278, 302, 308, 314, 328, 332, 338, 356, 374, 398, 404, 416, 428, 440, 458, 464, 482, 488, 494, 506, 518, 524, 530 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Hongze Li, Sums of one prime and two prime squares, Acta Arithmetica (2008), Volume: 134, Issue: 1, page 1-9.
Lilu Zhao, The additive problem with one prime and two squares of primes, Journal of Number Theory, Volume 135, February 2014, Pages 8-27.
EXAMPLE
10 is the first missing number since it is 2 + 2^2 + 2^2.
PROG
(PARI) isok2(n)=forprime(q=2, sqrtint(n), if(isprimepower(n-q^2)==2, return(0))); 1;
isok(n) = forprime(p=2, n-1, if (!isok2(n-p), return (0)); ); 1;
CROSSREFS
Cf. A214879.
Sequence in context: A226900 A111228 A324022 * A280595 A281942 A280594
KEYWORD
nonn
AUTHOR
Michel Marcus, Mar 05 2017
STATUS
approved

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Last modified June 22 21:37 EDT 2024. Contains 373610 sequences. (Running on oeis4.)