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A098757
Smallest available integer which fits into the repeating pattern 02468.
0
0, 2, 4, 6, 80, 24, 680, 246, 802, 46, 8024, 6802, 4680, 24680, 246802, 46802, 468024, 68024, 680246, 80246, 8024680, 2468024, 68024680, 24680246, 80246802, 4680246, 802468024, 680246802, 468024680, 2468024680, 24680246802, 4680246802
OFFSET
0,2
COMMENTS
a(n) must be chosen so its rightmost digit is not 8 (so that the next term won't start with 0). - Sam Alexander, Jan 04 2005
If n>=20, then a(n) is a(n-16) with one period 24680 (or a suitable cyclic permutation thereof) appended (or prepended, or inserted, whatever one prefers). [From Hagen von Eitzen, Jun 18 2009]
FORMULA
Let (c[0], c[1], ..., c[15]) = (8024600, 2468000, 68024000, 24680000, 80246000, 4680200, 802460000, 680240000, 468020000, 2468000000, 24680000000, 4680200000, 46802000000, 6802400000,68024000000,8024600000), i.e. c[r] = a[r+20] - a[r+4] for 0 <= r < 16. If n>=4, then writing n = 16*k + r + 4 with 0<=r<16 we have a(n) = floor( c[r]*100000^k/99999 ). [From Hagen von Eitzen, Jun 18 2009]
G.f.: -4 + 2 x - 2 x^2 + 6 x^3 + (4 + 6 x^2 + 80 x^4 + 24 x^5 + 680 x^6 + 246 x^7 + 802 x^8 + 46 x^9 + 8024 x^10 + 6802 x^11 + 4680 x^12 + 24680 x^13 + 246802 x^14 + 46802 x^15 + 68020 x^16 + 68024 x^17 + 80240 x^18 + 80246 x^19 + 24600 x^20 + 68000 x^21 + 24000 x^22 + 80000 x^23 + 46000 x^24 + 80200 x^25 + 60000 x^26 + 40000 x^27 + 20000 x^28 - 200000 x^30)/(1 - 100001 x^16 + 100000 x^32) [From Hagen von Eitzen, Jul 19 2009]
CROSSREFS
Sequence in context: A348152 A367854 A009257 * A335709 A056012 A259050
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, Oct 01 2004
EXTENSIONS
More terms from Sam Alexander, Jan 04 2005
More terms from Hagen von Eitzen, Jun 18 2009
STATUS
approved