A082669 Let p(n) = upper member of n-th pair of twin primes; sequence gives a(n) = p(n)*(p(n)-1)/2.

10, 21, 78, 171, 465, 903, 1830, 2628, 5253, 5886, 9591, 11325, 16290, 18528, 19701, 26106, 28920, 36585, 39903, 48828, 60726, 88410, 93528, 106953, 136503, 162735, 180300, 191271, 206403, 218130, 328455, 338253, 343206, 368511, 389403

Offset

0,1

Comments

This sequence also gives C(m, m-2) for all m such that m is the greater member of the n-th twin prime pair. - Christopher Tomaszewski (cmt1288(AT)comcast.net), Oct 26 2003

Let p(n) = upper member of n-th pair of twin primes; sequence gives a(n) = p(n)*(p(n)-1)/2. - Zerinvary Lajos, Mar 08 2007

Links

Table of n, a(n) for n=0..34.

Maple

ZL:=[]:for p from 1 to 890 do if (isprime(p) and isprime(p+2) ) then ZL:=[op(ZL), (binomial((p+2), p))]; fi; od; print(ZL); # Zerinvary Lajos, Mar 08 2007

Prog

(PARI) tpcomb2(n) = { forprime(x=3, n, if(isprime(x-2), print1((x)*(x-1)/2" ") ) )

Crossrefs

Sequence in context: A356761 A096564 A041196 * A215574 A146083 A321722

Adjacent sequences: A082666 A082667 A082668 * A082670 A082671 A082672

Keyword

easy,nonn

Author

Cino Hilliard, May 18 2003

Status

approved