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A082797
Smallest multiple of n beginning with 7.
7
7, 70, 72, 72, 70, 72, 7, 72, 72, 70, 77, 72, 78, 70, 75, 704, 714, 72, 76, 700, 714, 704, 713, 72, 75, 78, 702, 700, 725, 720, 713, 704, 726, 714, 70, 72, 74, 76, 78, 720, 738, 714, 731, 704, 720, 736, 705, 720, 735, 700, 714, 728, 742, 702, 715
OFFSET
1,1
COMMENTS
a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 8n, 9n, 11n, 12n, 13n, 14n, 15n, 16n, 17n, 18n, 21n, 22n, 23n, 24n, 25n, 26n, 27n, 31n, 32n, 33n, 34n, 35n, 41n, 42n, 43n, 44n, 51n, 52n, 53n, 61n, 62n}. [Charles R Greathouse IV, Mar 06 2011]
LINKS
MATHEMATICA
f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 7, m += n]; m]; Array[f, 55] (* Robert G. Wilson v *)
PROG
(PARI) a(n)=forstep(k=n, 62*n, n, if(Vec(Str(k))[1]=="7", return(k))) \\ Charles R Greathouse IV, Mar 06 2011
(Haskell)
a082797 n = until ((== 7) . a000030) (+ n) n
-- Reinhard Zumkeller, Mar 27 2012
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Apr 20 2003
EXTENSIONS
Corrected and extended by Sean A. Irvine, Mar 06 2011
STATUS
approved