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A135275 a(n) = prime(2n-1) + prime(2n) - prime(2n+1). 1
0, 1, 7, 13, 21, 27, 37, 41, 53, 65, 69, 75, 95, 101, 95, 121, 127, 143, 153, 161, 169, 187, 185, 207, 223, 231, 235, 251, 263, 275, 269, 305, 299, 321, 343, 345, 361, 373, 385, 391, 409, 425, 433, 445, 457, 459, 479, 493, 507, 517 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Original name was: Sum and difference of staircase primes according to the rule: bottom + top - next top.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

We list the primes in staircase fashion as in A135274. The right diagonal, RD(n), is the set of top primes and the left diagonal, LD(x), is the set of bottom primes. Then a(n) = LD(n+1) + RD(n) - RD(n+2).

a(n) = A096379(2*n-1). - R. J. Mathar, Sep 10 2016

MATHEMATICA

Table[Prime[n + 1] + Prime[n] - Prime[n + 2], {n, 1, 30}][[;; ;; 2]] (* G. C. Greubel, Oct 08 2016 *)

PROG

(PARI) g(n) = forstep(x=1, n, 2, y=prime(x+1)+ prime(x)- prime(x+2); print1(y", "))

(PARI) n=1; p=2; q=3; forprime(r=5, 1e3, if(n, print1(p+q-r", ")); n=!n; p=q; q=r) \\ Charles R Greathouse IV, Oct 08 2016

CROSSREFS

Cf. A096379, A135274.

Sequence in context: A054858 A269704 A157971 * A304005 A304947 A013652

Adjacent sequences:  A135272 A135273 A135274 * A135276 A135277 A135278

KEYWORD

nonn,easy

AUTHOR

Cino Hilliard, Dec 02 2007

EXTENSIONS

New name from Charles R Greathouse IV, Oct 08 2016

STATUS

approved

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Last modified November 24 10:26 EST 2020. Contains 338612 sequences. (Running on oeis4.)