A138042 Numbers n such that A096379(n)=A096379(n+1).

2, 7, 13, 19, 49, 69, 116, 182, 206, 225, 229, 236, 253, 265, 288, 315, 324, 352, 379, 390, 394, 435, 492, 497, 542, 551, 567, 625, 643, 658, 718, 754, 794, 920, 930, 935, 958, 966, 988, 1025, 1032, 1085, 1101, 1128, 1155, 1171, 1173, 1225, 1235, 1249

Offset

1,1

Comments

Numbers n such that prime(n)=2*prime(n+2)-prime(n+3).

Links

Zak Seidov, Table of n, a(n) for n = 1..1192, a(n)<50000.

Formula

a(n) = A066495(n) - 2.

Example

n=2: {prime(n), 2*prime(n+2)-prime(n+3)}={3,2*7-11},
n=7: {prime(7), 2*prime(9)-prime(10)}={17,2*23-29},
n=13: {prime(13), 2*prime(15)-prime(16)}={41,2*47-53},
n=19: {prime(19), 2*prime(21)-prime(22)}={67,2*73-79}.

Mathematica

Do[If[Prime[n]==2Prime[n+2]-Prime[n+3], Print[n]], {n, 1, 50000}]

Prog

(Scheme with Antti Karttunen's IntSeq-library)
(define A138042 (MATCHING-POS 1 1 (lambda (n) (= 2 (/ (+ (A000040 n) (A000040 (+ n 3))) (A000040 (+ n 2)))))))

Crossrefs

Cf. A066495, A096379.

Sequence in context: A331544 A237499 A231476 * A053977 A079381 A079382

Adjacent sequences: A138039 A138040 A138041 * A138043 A138044 A138045

Keyword

nonn

Author

Zak Seidov, Mar 02 2008

Extensions

Formula corrected by Antti Karttunen, Jul 13 2013

Status

approved