A251720 - OEIS

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A251720

a(n) = (p_n)^2 * p_{n+1}, where p_n is the n-th prime, A000040(n).

7

12, 45, 175, 539, 1573, 2873, 5491, 8303, 15341, 26071, 35557, 56129, 72283, 86903, 117077, 165731, 212341, 249307, 318719, 367993, 420991, 518003, 613121, 768337, 950309, 1050703, 1135163, 1247941, 1342553, 1621663, 2112899, 2351057, 2608891, 2878829, 3352351

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OFFSET

1,1

COMMENTS

Subsequence of A014612: a(1)=12=A014612(2), a(2)=45=A014612(10) - Zak Seidov, Apr 26 2016

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A000040(n) * A000040(n) * A000040(n+1).

a(n) = A000040(n) * A006094(n).

a(n) = A001248(n) * A000040(n+1).

MATHEMATICA

a251720[n_Integer] := Prime[#]^2*Prime[# + 1] & /@ Range[n]; a251720[35] (* Michael De Vlieger, Dec 14 2014 *)

#[[1]]^2 #[[2]]&/@Partition[Prime[Range[40]], 2, 1] (* Harvey P. Dale, Mar 12 2015 *)

PROG

(Scheme, three versions)

(define (A251720 n) (* (A000040 n) (A000040 n) (A000040 (+ 1 n))))

(define (A251720 n) (* (A000040 n) (A006094 n)))

(define (A251720 n) (* (A001248 n) (A000040 (+ n 1))))

CROSSREFS

Cf. A000040, A001248, A006094, A250477, A014612, A268733.

Sequence in context: A350116 A015237 A024223 * A199211 A331764 A372500

Adjacent sequences: A251717 A251718 A251719 * A251721 A251722 A251723

KEYWORD

nonn

AUTHOR

Antti Karttunen, Dec 14 2014

STATUS

approved