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A137507
a(n) = 100^[n/10] + 2*n*10^[n/10]: inspired by Engel expansion of Pi.
1
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 14000, 14200, 14400, 14600, 14800, 15000, 15200, 15400, 15600, 15800, 1060000, 1062000, 1064000, 1066000, 1068000, 1070000
OFFSET
0,2
LINKS
MATHEMATICA
Table[100^(Floor[n/10]) + 2*n*10^(Floor[n/10]), {n, 0, 50}] (* G. C. Greubel, Feb 23 2017 *)
PROG
(PARI) a(n) = (n+5 + 10^(floor((n+5)/10)))^2 - (n+5)^2; for (n=1, 30, print1(" "a(n)" ")) \\ changed n+5 to n. - M. F. Hasler, May 02 2008
(PARI) vector(30, n, n--; 2*n*10^(n\10) + 100^(n\10)) \\ M. F. Hasler, May 02 2008
CROSSREFS
Cf. A006784.
Sequence in context: A352547 A014261 A066640 * A061808 A248608 A362680
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by M. F. Hasler and N. J. A. Sloane, May 02 2008
STATUS
approved