A153022 Numbers n such that 1 plus the sum of squares of the first n primes is divisible by n+1.

6, 10, 150, 238, 56824, 665460, 18468766, 193274008, 635705422, 790546908, 33256634229, 66874977806, 68066767730

Offset: 1

Author

Ctibor O. Zizka, Dec 16 2008

Keywords

• nonn
• more

Comments

No further term <200000. [R. J. Mathar, Jan 17 2009]

a(11) > pi(10^11). [Donovan Johnson, Mar 10 2010]

a(14) > 118*10^9. - Robert Price, Apr 10 2013

Examples

			1 plus the sum of squares of the first 6 primes: (1 + 2^2 + 3^2 + ... + 13^2)/7 = 54, thus 6 is an element of the sequence.
		

Crossrefs

Cf. A111441, A045345, A140480

Formula

{n: n+1 | A024525(n) }. [R. J. Mathar, Jan 17 2009]

Extensions

a(5) from R. J. Mathar, Jan 17 2009

a(6)-a(10) from Donovan Johnson, Mar 10 2010

a(11)-a(13) from Robert Price, Apr 10 2013