A255230 Integers n such that n^2 = 2*x*(y-x), where x and y are consecutive terms in A014574.

4, 12, 48, 120, 468, 1260, 720, 2448, 10080, 12060, 15912, 7560, 18480, 7392, 9660, 27720, 33480, 14400, 25080, 36708, 10092, 34188, 42120, 83400, 29820, 20040, 67320, 114408, 206628, 67368, 72192, 102648, 152928, 51732, 59880, 152700, 106440, 100980, 171480

Offset: 1

Author

Neri Gionata, Feb 18 2015

Keywords

• nonn

Comments

n is a term if n^2 = 2*x*(y-x), where x and y are the averages of two consecutive twin prime pairs.

Examples

			48^2 = 2*192*(198-192), and 192 and 198 are consecutive terms in A014574, so 48 is in the sequence.
		

Crossrefs

Cf. A014574.

Programs

PARI

lista(nn) = {p=2; last = 0; forprime (q=3, nn, if (q-p==2, if (! last, last = p+1, new = p+1; val = new^2-last^2 - (new-last)^2; if (issquare(val), print1(sqrtint(val), ", ")); last = new; );); p=q;);} \\ Michel Marcus, Feb 18 2015

Extensions

More terms from Michel Marcus, Feb 18 2015