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 1-3 of 3 results.

A378893 Numbers that are a proper substring of the concatenation (with repetition) in increasing order of their prime factors.

Original entry on oeis.org

333, 22564, 113113, 210526, 252310, 1143241, 3331233, 3710027, 31373137, 217893044, 433100023, 2263178956
Offset: 1

Views

Author

Scott R. Shannon, Dec 10 2024

Keywords

Examples

			333 is a term as 333 = 3 * 3 * 37 = "3337" when concatenated, which contains "333" as a substring.
113113 is a term as 113113 = 7 * 11 * 13 * 113 = "71113113" when concatenated, which contains "113113" as a substring.
433100023 is a term as 433100023 = 433 * 1000231 = "4331000231" when concatenated, which contains "433100023" as a substring.

Crossrefs

Cf. A027746, A378894, A376078, A372309, A371958, A371696, A372046, A371641.

A378894 Numbers, when written in binary, that are a proper substring of the concatenation (with repetition) in increasing order of their prime factors, when written in binary.

Original entry on oeis.org

10, 57, 63, 355, 737, 921, 1526, 13803, 22008, 43364, 44016, 48895, 65151, 88032, 130545, 235929, 255987, 563207, 702460, 1456355, 2799617, 3020897, 3137557, 3774873, 4163463, 5697350, 5995862, 14176747, 42172441, 55933611, 87559273, 93206755, 108530173, 126474397, 180677710, 193337441, 249550095, 259779663, 533713761, 536378647, 715881440, 940339099, 1000732491
Offset: 1

Views

Author

Scott R. Shannon, Dec 10 2024

Keywords

Examples

			10 is a term as 10 = 1010_2 = 2 * 5 = 10_2 * 101_2 = "10101" when concatenated, which contains "1010" as a substring.
63 is a term as 63 = 111111_2 = 3 * 3 * 7 = 11_2 * 11_2 * 111_2 = "1111111" when concatenated, which contains "111111" as a substring.
1526 is a term as 1526 = 10111110110_2 = 2 * 7 * 109 = 10_2 * 111_2 * 1101101_2 = "101111101101" when concatenated, which contains "10111110110" as a substring.

Crossrefs

Cf. A027746, A378893, A376078, A372309, A371958, A371696, A372046, A371641.

A378950 Numbers that are a proper substring of the concatenation (with repetition) in decreasing order of their prime factors.

Original entry on oeis.org

95, 132, 995, 9995, 73332, 85713, 93115, 131131, 197591, 632812, 999995, 4285713, 8691315, 58730137, 99999995, 131373333, 507107133, 4870313015
Offset: 1

Views

Author

Scott R. Shannon, Dec 11 2024

Keywords

Comments

All numbers of the form 5*A055558(k), k>=1, are terms.

Examples

			95 is a term as 95 = 19 * 5 = "195" when concatenated, which contains "95" as a substring.
632812 is a term as 632812 = 563 * 281 * 2 * 2 = "56328122" when concatenated, which contains "632812" as a substring.
4870313015 is a term as 4870313015 = 748703 * 1301 * 5 = "74870313015" when concatenated, which contains "4870313015" as a substring.

Crossrefs

Cf. A027746, A378893, A378894, A376078, A372309.
Showing 1-3 of 3 results.

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

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