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.

Previous Showing 21-30 of 30 results.

A299983 Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 3, and no term occurs twice.

Original entry on oeis.org

0, 3, 10, 13, 17, 6, 7, 16, 14, 9, 4, 19, 11, 2, 1, 12, 18, 5, 8, 15, 20, 23, 30, 33, 40, 43, 50, 53, 60, 63, 67, 26, 27, 36, 37, 46, 47, 56, 57, 66, 64, 29, 24, 39, 34, 49, 44, 59, 54, 69, 61, 22, 21, 32, 31, 42, 41, 52, 51, 62, 68, 25, 28, 35, 38, 45, 48, 55, 58, 65, 70, 73, 80, 83, 90, 93, 100, 103, 110, 113, 117, 76, 77, 86, 87, 96, 97, 106, 107
Offset: 0

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the nonnegative integers.

Crossrefs

Cf. A299973 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982, ..., A299988, A299969 (digit 0, 2, ..., 9).

Programs

  • PARI
    a(n,f=1,d=3,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299987 Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 7, and no term occurs twice.

Original entry on oeis.org

0, 7, 10, 17, 20, 27, 30, 37, 33, 4, 3, 14, 13, 24, 23, 34, 36, 1, 6, 11, 16, 21, 26, 31, 39, 8, 9, 18, 19, 28, 29, 38, 32, 5, 2, 15, 12, 25, 22, 35, 40, 47, 50, 57, 60, 67, 70, 77, 80, 87, 83, 44, 43, 54, 53, 64, 63, 74, 73, 84, 86, 41, 46, 51, 56, 61, 66, 71, 76, 81, 89, 48, 49, 58, 59, 68, 69, 78, 79, 88, 82, 45, 42, 55, 52, 65, 62, 75, 72, 85, 90
Offset: 0

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the nonnegative integers.

Crossrefs

Cf. A299977 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982..A299988, A299969 (digit 0, 2..8, 9).

Programs

  • PARI
    a(n,f=1,d=7,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299974 Lexicographic first sequence of positive integers such that a(n) + a(n+1) has a digit 4, and no term occurs twice.

Original entry on oeis.org

1, 3, 11, 13, 21, 19, 5, 9, 15, 25, 16, 8, 6, 18, 22, 2, 12, 28, 14, 10, 4, 20, 23, 17, 7, 27, 37, 47, 57, 67, 73, 31, 33, 41, 43, 51, 53, 61, 63, 71, 69, 35, 29, 45, 39, 55, 49, 65, 59, 75, 66, 38, 26, 48, 36, 58, 46, 68, 56, 78, 62, 32, 42, 52, 72, 70, 24, 30, 34, 40, 44, 50, 54, 60, 64, 76, 88, 86, 98, 96, 108, 106, 118, 116, 124, 80, 74, 90, 84
Offset: 1

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the positive integers.

Crossrefs

Cf. A299984 (analog with nonnegative terms), A299957 (analog with digit 1), A299971, A299972, ..., A299979 (digit 0, 2, ..., 9).

Programs

  • PARI
    a(n,f=1,d=4,a=1,u=[a])={for(n=2,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299975 Lexicographic first sequence of positive integers such that a(n) + a(n+1) has a digit 5, and no term occurs twice.

Original entry on oeis.org

1, 4, 11, 14, 21, 24, 26, 9, 6, 19, 16, 29, 22, 3, 2, 13, 12, 23, 27, 8, 7, 18, 17, 28, 25, 10, 5, 20, 15, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 76, 39, 36, 49, 46, 59, 56, 69, 66, 79, 71, 34, 31, 44, 41, 54, 51, 64, 61, 74, 77, 38, 37, 48, 47, 58, 57, 68, 67, 78, 72, 33, 32, 43, 42, 53, 52, 63, 62, 73, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125
Offset: 1

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the positive integers.

Crossrefs

Cf. A299985 (analog with nonnegative terms), A299957 (analog with digit 1), A299971, A299972, ..., A299979 (digit 0, 2, ..., 9).

Programs

  • PARI
    a(n,f=1,d=5,a=1,u=[a])={for(n=2,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299976 Lexicographic first sequence of positive integers such that a(n) + a(n+1) has a digit 6, and no term occurs twice.

Original entry on oeis.org

1, 5, 11, 15, 21, 25, 31, 29, 7, 9, 17, 19, 27, 33, 3, 13, 23, 37, 24, 2, 4, 12, 14, 22, 34, 26, 10, 6, 20, 16, 30, 32, 28, 8, 18, 38, 48, 58, 68, 78, 82, 44, 42, 54, 52, 64, 62, 74, 72, 84, 76, 40, 36, 50, 46, 60, 56, 70, 66, 80, 81, 35, 41, 45, 51, 55, 61, 65, 71, 75, 85, 77, 39, 47, 49, 57, 59, 67, 69, 87, 73, 43, 53, 63, 83, 79, 86, 90, 96, 100
Offset: 1

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the positive integers.

Crossrefs

Cf. A299986 (analog with nonnegative terms), A299957 (analog with digit 1), A299971, A299972, ..., A299979 (digit 0, 2, ..., 9).

Programs

  • PARI
    a(n,f=1,d=6,a=1,u=[a])={for(n=2,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299977 Lexicographic first sequence of positive integers such that a(n) + a(n+1) has a digit 7, and no term occurs twice.

Original entry on oeis.org

1, 6, 11, 16, 21, 26, 31, 36, 34, 3, 4, 13, 14, 23, 24, 33, 37, 10, 7, 20, 17, 30, 27, 40, 32, 5, 2, 15, 12, 25, 22, 35, 38, 9, 8, 19, 18, 29, 28, 39, 48, 49, 58, 59, 68, 69, 78, 79, 88, 82, 45, 42, 55, 52, 65, 62, 75, 72, 85, 86, 41, 46, 51, 56, 61, 66, 71, 76, 81, 89, 83, 44, 43, 54, 53, 64, 63, 74, 73, 84, 87, 50, 47, 60, 57, 70, 67, 80, 77, 90, 97
Offset: 1

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the positive integers.

Crossrefs

Cf. A299987 (analog with nonnegative terms), A299957 (analog with digit 1), A299971, A299972, ..., A299979 (digit 0, 2, ..., 9).

Programs

  • PARI
    a(n,f=1,d=7,a=1,u=[a])={for(n=2,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299984 Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 4, and no term occurs twice.

Original entry on oeis.org

0, 4, 10, 14, 20, 21, 3, 1, 13, 11, 23, 17, 7, 27, 15, 9, 5, 19, 22, 2, 12, 28, 6, 8, 16, 18, 24, 25, 29, 35, 39, 45, 49, 55, 59, 65, 69, 71, 33, 31, 43, 41, 53, 51, 63, 61, 73, 67, 37, 47, 57, 77, 64, 30, 34, 40, 44, 50, 54, 60, 74, 66, 38, 26, 48, 36, 58, 46, 68, 56, 78, 62, 32, 42, 52, 72, 70, 75, 79, 85, 89, 95, 99, 105, 109, 115, 119, 121, 83
Offset: 0

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the nonnegative integers.

Crossrefs

Cf. A299974 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982, ..., A299988, A299969 (digit 0, 2, ..., 8, 9).

Programs

  • PARI
    a(n,f=1,d=4,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299985 Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 5, and no term occurs twice.

Original entry on oeis.org

0, 5, 10, 15, 20, 25, 26, 9, 6, 19, 16, 29, 21, 4, 1, 14, 11, 24, 27, 8, 7, 18, 17, 28, 22, 3, 2, 13, 12, 23, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 76, 39, 36, 49, 46, 59, 56, 69, 66, 79, 71, 34, 31, 44, 41, 54, 51, 64, 61, 74, 77, 38, 37, 48, 47, 58, 57, 68, 67, 78, 72, 33, 32, 43, 42, 53, 52, 63, 62, 73, 80, 85, 90, 95, 100, 105, 110, 115, 120
Offset: 0

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the nonnegative integers.

Crossrefs

Cf. A299975 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982..A299988, A299969 (digit 0, 2..8, 9).

Programs

  • PARI
    a(n,f=1,d=5,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A299986 Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 6, and no term occurs twice.

Original entry on oeis.org

0, 6, 10, 16, 20, 26, 30, 31, 5, 1, 15, 11, 25, 21, 35, 27, 9, 7, 19, 17, 29, 32, 4, 2, 14, 12, 24, 22, 34, 28, 8, 18, 38, 23, 3, 13, 33, 36, 40, 46, 50, 56, 60, 66, 70, 76, 80, 81, 45, 41, 55, 51, 65, 61, 75, 71, 85, 77, 39, 37, 49, 47, 59, 57, 69, 67, 79, 82, 44, 42, 54, 52, 64, 62, 74, 72, 84, 78, 48, 58, 68, 88, 73, 43, 53, 63, 83, 86, 90, 96, 100
Offset: 0

Views

Author

M. F. Hasler and Eric Angelini, Feb 22 2018

Keywords

Comments

A permutation of the nonnegative integers.

Crossrefs

Cf. A299976 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982..A299988, A299969 (digit 0, 2..8, 9).

Programs

  • PARI
    a(n,f=1,d=6,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}

A362064 Lexicographically earliest sequence of distinct positive integers such that the digit "1" is neither present in a(n) nor in a(n) + a(n+1).

Original entry on oeis.org

2, 3, 4, 5, 20, 6, 22, 7, 23, 9, 24, 8, 25, 27, 26, 28, 29, 30, 32, 33, 34, 35, 37, 36, 38, 39, 40, 42, 43, 44, 45, 47, 46, 48, 49, 50, 200, 52, 202, 53, 203, 54, 204, 55, 205, 57, 206, 56, 207, 58, 208, 59, 209, 60, 220, 62, 222, 63, 223, 64, 224, 65, 225, 67
Offset: 1

Views

Author

Eric Angelini and Cécile Angelini, Apr 07 2023

Keywords

Examples

			2 + 3 = 5; 3 + 4 = 7; 4 + 5 = 9; but as 5 + 6 = 11 we cannot use 6 nor 7 (sum 12), 8 (sum 13) and 9 (sum 14); we cannot use the integers 10 to 19 (as a 1 is present in them), so a(5) = 20 as 5 + 20 = 25, etc.

Links

Crossrefs

Cf. A052383, A299957.

Programs

  • Python
    from itertools import islice
def jump1(n):
    s = str(n)
    return n if "1" not in s else int(s[:(i:=s.index("1"))]+"2"+"0"*(len(s)-i-1))
def agen(): # generator of terms
    an, aset, mink = 2, {2}, 3
    while True:
        yield an
        k = mink
        while k in aset or "1" in str(an+k): k = jump1(k+1)
        an = k
        aset.add(an)
        while mink in aset: mink = jump1(mink+1)
print(list(islice(agen(), 64))) # Michael S. Branicky, Apr 07 2023

Extensions

a(27) and beyond from Michael S. Branicky, Apr 07 2023
Previous Showing 21-30 of 30 results.

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