A145198 - OEIS

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A145198

a(n) is the least number not already in the sequence and not the product of consecutive terms in the sequence.

1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..10000

PROG

(PARI) {m=72; v=vector(m); z=2*m; u=vectorsmall(z); k=1; for(n=1, m, while(u[k], k++); v[n]=k; u[k]=1; j=n-1; p=k; while(j>0&&(p=p*v[j])<=z, u[p]=1; j--)); for(i=1, m, print1(v[i], ", "))} \\ Klaus Brockhaus, Oct 06 2008

HP 49G calculator program from Gerald Hillier, Oct 24 2008

<< 0 OVER NDUPN

->LIST DUPDUP + 1 0

0 -> M V U K J P

<< 1 M

FOR N K

WHILE U OVER

GET

REPEAT 1 +

END 'K' STO V

N K PUT 'V' STO U K

1 PUT N 1 - 'J' STO

K 'P' STO

WHILE J 0 >

THEN P V J

GET * DUP 'P' STO M

2 * <=

ELSE 0

END

REPEAT P 1

PUT J 1 - 'J' STO

END 'U' STO

NEXT V

CROSSREFS

Cf. A002048, A145278 (complement).

Sequence in context: A121229 A286291 A286926 * A083210 A345913 A187392

Adjacent sequences: A145195 A145196 A145197 * A145199 A145200 A145201

KEYWORD

nonn

AUTHOR

Gerald Hillier, Oct 04 2008

EXTENSIONS

Extended by Klaus Brockhaus, Oct 06 2008

STATUS

approved