cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A151995 a(1)=1; thereafter a(n) is smallest positive number not already in the sequence such that the sum a(1)+...+a(n) divides the concatenation a(1)...a(n).

Original entry on oeis.org

1, 2, 6, 250488, 19986, 118030, 133970, 693810, 2231328, 3407286, 5733260, 25176334, 75529002, 1913932644, 2692452, 5413116264, 6766395330, 2492882490, 9544178676, 19819882608, 10086515692, 10541120510, 4147755864, 6025730266
Offset: 1

Views

Author

N. J. A. Sloane, Oct 07 2009, based on a posting to the Sequence Fans Mailing List by Eric Angelini, Sep 29 2009

Keywords

Examples

			1+2 (=3) divides 12 --> HIT
1+2+3 (=6) does not divide 123
1+2+4 (=7) does not divide 124
1+2+5 (=8) does not divide 125
1+2+6 (=9) divides 126 --> HIT
...
126250488 == (1+2+6+250488) * 504
...
The sum of the first 14 terms, 2027226147, divides their concatenation
1262504881998611803013397069381022313283407286573326025176334755290021913932644,
giving a quotient of
622774565071062988323520804204101612390759720490782533881916606559052.

Crossrefs

Cf. A152210, A166064, A165770, A165771.

Extensions

More terms from Jack Brennen, John W. Layman, Charles R Greathouse IV and Robert G. Wilson v, Sep 30 2009. Jack Brennen found a(14).
Definition corrected by Zak Seidov, Oct 08 2009
a(15)-a(24) from Donovan Johnson, Jul 20 2010

A152210 a(1)=1; thereafter a(n) is smallest number > a(n-1) such that the sum a(1)+...+a(n) divides the concatenation a(1)...a(n).

Original entry on oeis.org

1, 2, 6, 250488, 279786, 1060566, 1414088, 1767610, 2447460, 10031652, 10356624, 50373066, 155962698, 193715622, 375287934, 759659778, 3125214762, 3252158280, 21173281128, 22937721222, 104101965546, 164092928742, 284358161736
Offset: 1

Views

Author

N. J. A. Sloane, Oct 07 2009, based on a posting to the Sequence Fans Mailing List by Eric Angelini, Sep 29 2009

Keywords

Comments

See A151995 for the nonmonotonic version.

Examples

			1+2 (=3) divides 12 --> HIT
1+2+3 (=6) does not divide 123
1+2+4 (=7) does not divide 124
1+2+5 (=8) does not divide 125
1+2+6 (=9) divides 126 --> HIT
...

Crossrefs

Cf. A151995, A166064, A165770, A165771.

Extensions

Corrected by Zak Seidov, Oct 08 2009
a(14)-a(20) from Donovan Johnson, Jul 20 2010
a(21)-a(23) from Max Alekseyev, Jun 18 2011
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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