id:A129389 - OEIS Search Results

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Numbers n such that mean of 5 consecutive squares starting with n^2 is prime.

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1, 7, 13, 19, 31, 37, 43, 55, 79, 97, 103, 109, 115, 121, 145, 169, 217, 223, 235, 241, 247, 253, 271, 295, 301, 307, 319, 343, 349, 361, 367, 373, 385, 415, 421, 427, 439, 445, 451, 475, 499, 511, 547, 553, 559, 571, 601, 607, 649, 673, 679, 697, 709, 751 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Sum of 5 consecutive squares starting with n^2 is equal to 5(6 + 4n + n^2) and mean is (6 + 4*n + n^2)=(n+2)^2+2. Hence a(n)= A067201(n+2).`
	EXAMPLE	`(1^2+...+5^2)/5=11 prime, (7^2+...+11^2)/5=83 prime, (13^2+...+17^2)/5=227 prime.`
	CROSSREFS	`Cf. A056899, A067201, A129388.` `Sequence in context: A004611 A133290 A038590 this_sequence A107925 A002476 A123365` `Adjacent sequences: A129386 A129387 A129388 this_sequence A129390 A129391 A129392`
	KEYWORD	`nonn`
	AUTHOR	`Zak Seidov (zakseidov(AT)gmail.com), Apr 12 2007`

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Last modified November 22 20:51 EST 2009. Contains 167312 sequences.

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