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A027473 Second column of A027466. 9
1, 14, 147, 1372, 12005, 100842, 823543, 6588344, 51883209, 403536070, 3107227739, 23727920916, 179936733613, 1356446145698, 10173346092735, 75960984159088, 564959819683217, 4187349251769726, 30939858360298531 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..300

Frank Ellermann, Illustration of binomial transforms.

FORMULA

a(n) = n*7^(n-1).

a(n) = 14*a(n-1) - 49*a(n-2) with a(1) = 1, a(2) = 14.

a(n) = A003415(7^n). - Bruno Berselli, Oct 22 2013

From Amiram Eldar, Oct 28 2020: (Start)

Sum_{n>=1} 1/a(n) = 7*log(7/6).

Sum_{n>=1} (-1)^(n+1)/a(n) = 7*log(8/7). (End)

MATHEMATICA

Join[{a=1, b=14}, Table[c=14*b-49*a; a=b; b=c, {n, 60}]] (* Vladimir Joseph Stephan Orlovsky, Feb 01 2011 *)

PROG

(MAGMA) [n*7^(n-1): n in [1..35]]; // Vincenzo Librandi, Jun 06 2011

CROSSREFS

Cf. A001787, A003415, A053464, A053469.

Sequence in context: A241169 A209347 A132934 * A002451 A302994 A207259

Adjacent sequences:  A027470 A027471 A027472 * A027474 A027475 A027476

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 29 2001

Offset changed from 2 to 1 by Vincenzo Librandi, Jun 06 2011

STATUS

approved

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Last modified November 28 22:01 EST 2021. Contains 349415 sequences. (Running on oeis4.)